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In the Linux kernel, the following vulnerability has been resolved: xfs: don't wrap around quota ids in dqiterate LOLLM noticed that q_id is an unsigned 32-bit variable. If it happens to be set to XFS_DQ_ID_MAX due to a filesystem that actually has a dquot for ID_MAX, then this addition will truncate to zero and the iteration starts over. Fix this by casting to u64.

In the Linux kernel, the following vulnerability has been resolved: KVM: arm64: nv: Avoid dereferencing NULL VNCR pseudo-TLB VNCR TLB invalidation occurs from MMU notifiers or TLBI instructions, and either can race against a vcpu not being onlined yet (no pseudo-TLB allocated). Similarly, the TLB might be invalid, and the invalidation should be skipped in this case. Both kvm_invalidate_vncr_ipa() and kvm_invalidate_vncr_va() are expected to perform the same checks, except that the latter doesn't check for the allocation and blindly dereferences the pointer. Solve this by introducing a new iterator built on top of the usual kvm_for_each_vcpu() that checks for both of the above conditions, and convert the two users to it.

In the Linux kernel, the following vulnerability has been resolved: mm: do file ownership checks with the proper mount idmap Ever since idmapped mounts were introduced, inode ownership checks (for side-channel protection) in mincore() and madvise(MADV_PAGEOUT) were done against the nop_mnt_idmap, which completely ignores the file's mount's idmap. This results in odd edgecases like: 1) mount/bind-mount with an idmap userA:userB:1 2) userB runs an owner_or_capable() check on file that is owned by userA on-disk/in-memory, but owned by userB after idmap translation 3) owner_or_capable() mysteriously fails as the correct idmap wasn't supplied In the case of mincore/madvise MADV_PAGEOUT, this is usually benign, because file_permission(file, MAY_WRITE) will probably succeed, as it uses the proper idmap internally, but it does not need to be the case on e.g a 0444 file where even the owner itself doesn't have permissions to write to it. Since this is clearly not trivial to get right, introduce a file_owner_or_capable() that can carry the correct semantics, and switch the various users in mm to it. The issue was found by manual code inspection & an off-list discussion with Jan Kara.

In the Linux kernel, the following vulnerability has been resolved: KVM: arm64: Don't leak PFN when kvm_translate_vncr() races MMU notifier In the case that kvm_translate_vncr() races with an MMU notifier the early return does not release a reference on the faulted in PFN. Add the necessary call to kvm_release_faultin_page() for the unused PFN.

In the Linux kernel, the following vulnerability has been resolved: crypto: ccp - Do not initialize SNP for SEV ioctls Sashiko notes: > if SEV initialization fails and KVM is actively running normal VMs, could a > userspace process trigger this code path via /dev/sev ioctls (e.g., > SEV_PDH_GEN) and zero out MSR_VM_HSAVE_PA globally? Would the next VMRUN > execution for an active VM trigger a general protection fault and crash the > host? sev_move_to_init_state() is called for ioctls requiring only SEV firmware: SEV_PEK_GEN, SEV_PDH_GEN, SEV_PEK_CSR, SEV_PEK_CERT_IMPORT, and SEV_PDH_CERT_EXPORT. After the firmware command, it does SEV_SHUTDOWN on the SEV firmware. Since these commands do not require SNP to be initialized, skip it by calling __sev_platform_init_locked() which only initializes the SEV firmware. This way SNP is not Initialized at all, and HSAVE_PA is not cleared. The previous code saved any SEV initialization firmware error to init_args.error and then threw it away and hardcoded the return value of INVALID_PLATFORM_STATE regardless of the real firmware error. This patch changes it to surface the underlying error, which is hopefully both more useful and doesn't cause any problems. Note that it is still safe to call __sev_firmware_shutdown() directly: it calls __sev_snp_shutdown_locked(), which skips SNP shutdown if SNP was not initialized.

In the Linux kernel, the following vulnerability has been resolved: x86/mm: Fix freeing of PMD-sized vmemmap pages Commit bf9e4e30f353 ("x86/mm: use pagetable_free()"), switched from freeing non-boot page tables through __free_pages() to pagetable_free(). However, the function is also called to free vmemmap pages. Given that vmemmap pages are not page tables, already the page_ptdesc(page) is wrong. But worse, pagetable_free() calls: __free_pages(page, compound_order(page)); Since vmemmap pages are not compound pages (see vmemmap_alloc_block()) -- except for HVO, which doesn't apply here -- only first page of a PMD-sized vmemmap page is freed, leaking the other ones. Fix it by properly decoupling pagetable and vmemmap freeing. free_pagetable() no longer has to mess with SECTION_INFO, as only the vmemmap is marked like that in register_page_bootmem_memmap(). The indentation in remove_pmd_table() is messed up. Fix that while touching it. Bootmem info handling will soon be fixed up. For now, handle it similar to free_pagetable(), just avoiding the ifdef. [ dhansen: changelog munging. More imperative voice ]

In the Linux kernel, the following vulnerability has been resolved: HID: wacom: fix slab-out-of-bounds write in wacom_wac_queue_insert wacom_wac_queue_insert() calls kfifo_skip() in a loop when the kfifo doesn't have enough space for the incoming report. If the kfifo is empty, kfifo_skip() reads stale data left in the kmalloc'd buffer via __kfifo_peek_n() and interprets it as a record length, advancing fifo->out by that garbage value. This corrupts the internal kfifo state, causing kfifo_unused() to return a value much larger than the actual buffer size, which bypasses __kfifo_in_r()'s guard: if (len + recsize > kfifo_unused(fifo)) return 0; kfifo_copy_in() then performs an out-of-bounds memcpy, writing up to 3842 bytes past the 256-byte buffer. Add a !kfifo_is_empty() condition to the while loop so kfifo_skip() is never called on an empty fifo, and check the return value of kfifo_in() to reject reports that are too large for the fifo.

In the Linux kernel, the following vulnerability has been resolved: netfilter: handle unreadable frags sashiko reports: When an skb with unreadable fragments (such as from devmem TCP, where skb_frags_readable(skb) returns false) is processed by the u32 module, skb_copy_bits() will safely return a negative error code [..] xt_u32: bail out with hotdrop in this case. gather_frags: return -1, just as if we had no fragment header. nfnetlink_queue: restrict to the linear part. nfnetlink_log: restrict to the linear part. v2: - skb_zerocopy helpers don't copy readable flag, i.e. nfnetlink_queue is broken too xt_u32 shouldn't return true if hotdrop was set.

In the Linux kernel, the following vulnerability has been resolved: ntfs: avoid calling post_write_mst_fixup() for invalid index_block ntfs_icx_ib_sync_write() calls post_write_mst_fixup() when ntfs_ib_write() returns an error, intending to restore the buffer after a failed write. However, ntfs_ib_write() returns an error immediately if pre_write_mst_fixup() validation fails. The caller, ntfs_icx_ib_sync_write(), interprets any error as a write failure requiring rollback. It does not differentiate between I/O errors and validation failures, and calls post_write_mst_fixup() anyway. Since post_write_mst_fixup() assumes that the index_block contents is correct, it doesn't perform the boundary checks, which results in out-of-bounds memory access. An attacker can craft a malicious NTFS image with: - large index_block.usa_ofs offset, pointing outside the ntfs_record - index_block.usa_count = 0, causing integer underflow - or index_block.usa_count larger than actual number of sectors in the ntfs_record, causing out-of-bounds access KASAN reports describing the memory corruption: ================================================================== BUG: KASAN: slab-out-of-bounds in post_write_mst_fixup+0x19c/0x1d0 Read of size 2 at addr ffff8881586c9018 by task p/9428 Call Trace: <TASK> dump_stack_lvl+0x100/0x190 print_report+0x139/0x4ad ? post_write_mst_fixup+0x19c/0x1d0 ? __virt_addr_valid+0x262/0x500 ? post_write_mst_fixup+0x19c/0x1d0 kasan_report+0xe4/0x1d0 ? post_write_mst_fixup+0x19c/0x1d0 post_write_mst_fixup+0x19c/0x1d0 ntfs_icx_ib_sync_write+0x179/0x220 ntfs_inode_sync_filename+0x83d/0x1080 __ntfs_write_inode+0x1049/0x1480 ntfs_file_fsync+0x131/0x9b0 ================================================================== BUG: KASAN: slab-out-of-bounds in post_write_mst_fixup+0x1aa/0x1d0 Write of size 2 at addr ffff8881586c91fe by task p/9428 Call Trace: <TASK> dump_stack_lvl+0x100/0x190 print_report+0x139/0x4ad ? post_write_mst_fixup+0x1aa/0x1d0 ? __virt_addr_valid+0x262/0x500 ? post_write_mst_fixup+0x1aa/0x1d0 kasan_report+0xe4/0x1d0 ? post_write_mst_fixup+0x1aa/0x1d0 post_write_mst_fixup+0x1aa/0x1d0 ntfs_icx_ib_sync_write+0x179/0x220 ntfs_inode_sync_filename+0x83d/0x1080 __ntfs_write_inode+0x1049/0x1480 ntfs_file_fsync+0x131/0x9b0 ================================================================== Let's move the post_write_mst_fixup() call to ntfs_ib_write(). The ntfs_ib_write() function calls pre_write_mst_fixup() at the beginning. If the index_block contents is invalid, pre_write_mst_fixup() fails and ntfs_ib_write() returns early without calling post_write_mst_fixup() on bad index_block.

In the Linux kernel, the following vulnerability has been resolved: rust: block: fix GenDisk cleanup paths GenDiskBuilder::build() still has fallible work after __blk_mq_alloc_disk(), but its error path only recovers the foreign queue data. That leaks the temporary gendisk and request_queue until later teardown. If the caller moved the last Arc<TagSet<T>> into build(), the leaked queue can retain blk-mq state after the tag set is dropped. Fix the pre-registration failure path by dropping the temporary gendisk reference with put_disk() before recovering queue_data, so disk_release() can tear down the owned queue. Also pair GenDisk::drop() with put_disk() after del_gendisk(). Once a Rust GenDisk has been added with device_add_disk(), del_gendisk() only unregisters it; the final gendisk reference still has to be dropped to complete the release path.

CVE-2026-64468 is a use-after-free vulnerability in the Linux kernel's binder driver, specifically in the binder_free_transaction() function. The issue arises because the target process pointer (t->to_proc) can be freed after the lock protecting it is released, leading to a use-after-free when its inner lock is accessed. This flaw has been fixed by pinning the target thread to ensure the target process remains alive during the operation.

In the Linux kernel, the following vulnerability has been resolved: KVM: x86: hyper-v: Bound the bank index when querying sparse banks When checking if a VP ID is included in a sparse bank set, explicitly check that the ID can actually be contained in a sparse bank (the TLFS allows for a maximum of 64 banks of 64 vCPUs each). When handling a paravirtual TLB flush for L2, the VP ID is copied verbatim from the enlightened VMCS, without any bounds check, i.e. isn't guaranteed to be under the limit of 4096. Failure to check the bounds of the VP ID leads to an out-of-bounds read when testing the sparse bank, and super strictly speaking could lead to KVM performing an unnecessary TLB flush for an L2 vCPU. ================================================================== BUG: KASAN: use-after-free in hv_is_vp_in_sparse_set+0x85/0x100 [kvm] Read of size 8 at addr ffff88811ba5f598 by task hyperv_evmcs/2802 CPU: 12 UID: 1000 PID: 2802 Comm: hyperv_evmcs Not tainted 7.1.0-rc2 #7 PREEMPT Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 0.0.0 02/06/2015 Call Trace: <TASK> dump_stack_lvl+0x51/0x60 print_report+0xcb/0x5d0 kasan_report+0xb4/0xe0 kasan_check_range+0x35/0x1b0 hv_is_vp_in_sparse_set+0x85/0x100 [kvm] kvm_hv_flush_tlb+0xe9e/0x16c0 [kvm] kvm_hv_hypercall+0xe6b/0x1e60 [kvm] vmx_handle_exit+0x485/0x1b60 [kvm_intel] kvm_arch_vcpu_ioctl_run+0x22e3/0x5070 [kvm] kvm_vcpu_ioctl+0x5d0/0x10c0 [kvm] __x64_sys_ioctl+0x129/0x1a0 do_syscall_64+0xb9/0xcf0 entry_SYSCALL_64_after_hwframe+0x4b/0x53 RIP: 0033:0x7f0e62d1a9bf </TASK> The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0xffffffffffffffff pfn:0x11ba5f flags: 0x4000000000000000(zone=1) raw: 4000000000000000 0000000000000000 00000000ffffffff 0000000000000000 raw: ffffffffffffffff 0000000000000000 00000000ffffffff 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff88811ba5f480: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ffff88811ba5f500: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff >ffff88811ba5f580: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ^ ffff88811ba5f600: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ffff88811ba5f680: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ================================================================== Disabling lock debugging due to kernel taint Opportunistically add a compile time assertion to ensure the maximum number of sparse banks exactly matches the number of possible bits in the passed in mask. [sean: add KASAN splat, drop comment, add assert, massage changelog]

The kernel-rt packages provide the Real Time Linux Kernel, which enables fine-tuning for systems with extremely high determinism requirements. Security Fix(es): * kernel: KVM: x86: Don't (re)check L1 intercepts when completing userspace I/O (CVE-2025-40026) * kernel: xfrm single-frag length not properly limited * kernel: dm log: fix out-of-bounds write due to region_count overflow (CVE-2026-53059) * kernel: tipc: fix double-free in tipc_buf_append() (CVE-2026-52993)

Arbitrary Class Instantiation via XML Feature Generator Descriptor and Format Name in Apache OpenNLP Versions Affected: - before 2.5.10 - before 3.0.0-M5 Description: Three code paths in Apache OpenNLP load a class by its fully-qualified name via Class.forName() and invoke its no-arg constructor without any prior validation of the class name or its type.  The affected paths are: (1) GeneratorFactory, which reads the class attribute of generator elements in an XML feature generator descriptor; such descriptors are embedded as artifacts in model archives (e.g. TokenNameFinder and POSTagger models) and are parsed during model loading, so an attacker who can supply a crafted model archive controls the class name directly. (2) StreamFactoryRegistry.getFactory(Class, String), which falls back to interpreting an unregistered format name as the fully-qualified class name of an ObjectStreamFactory; this is exploitable in applications that pass untrusted format names (e.g. exposing the -format parameter of the command-line tooling to external input). (3) StringInterners, which instantiates the interner implementation named by the opennlp.interner.class system property; this value is normally deployer-controlled, so it is hardened as defense in depth rather than being independently attacker-reachable. Exploitation requires a class with attacker-useful side effects in its static initializer or no-arg constructor (JNDI lookup, outbound network I/O, filesystem access) to be present on the classpath, so this is not drop-in remote code execution. T Mitigation: Upgrade to a fixed release. The fix routes all three paths through ExtensionLoader.instantiateExtension(...), which consults a package-prefix allowlist before Class.forName() is invoked, so a disallowed class is never loaded, initialized, or constructed. Classes under the opennlp. prefix remain permitted by default. Deployments that load models referencing feature generator factories, object stream factories, or string interners outside opennlp.* must opt those packages in, either programmatically via ExtensionLoader.registerAllowedPackage(String) before the first model load, or by setting the OPENNLP_EXT_ALLOWED_PACKAGES system property to a comma-separated list of allowed package prefixes. Users who cannot upgrade immediately should ensure all model files and format names are sourced from trusted origins and should audit their classpath for classes with side-effecting static initializers or constructors.

GNU coreutils unexpand is vulnerable to a heap-based buffer overflow due to an integer overflow during buffer allocation when processing large tab stop (-t) values. The multiplication used to calculate the allocation size can wrap around, resulting in an undersized buffer. When processing crafted input, subsequent writes exceed the allocated memory, leading to an out‑of‑bounds heap write. When running GNU coreutils unexpand with attacker-provided large tab stop (-t) arguments, this behavior leads to a crash and potentially achieve a heap write primitive depending on memory layout. This issue has been fixed in the commit b60a159fdc5bfcf9988d3a4cb6f53abe8ad5d35d

Welcome to this week’s edition of the Threat Source newsletter. Lately I've found myself thinking a lot about the Australian TV series Mr. Inbetween (IMDb 8.7/10) — not because I'm a hitman for hire, but because I literally feel in-between. Specifically, in-between what I'd call the "pre-Mythos" and “post-Mythos” eras. We've crossed a capability threshold, and it's not just one model family driving that — Codex 5.3 and GPT-5.5 deliver comparable or better performance , and Tulongfeng or GLM-5.2 (an incredibly powerful open-weight model, MIT-licensed) show the frontier isn't limited to closed models anymore. On the other side of that line, real-world impact hasn't caught up yet and we're living in an artificial buffer zone. For me, defining the “pre-” and “post-” status comes down to the gap between "vulnerability discovery" and "vulnerability publication." Last week’s Patch Tuesday gave a signal of change, as Joe pointed out , so maybe the buffer zone has come to an end. Let's dive into the 2026 Q2 stats. As in past years, we're seeing a steeper curve than the year before — a solid 49% YoY growth, though still not the hockey-stick moment I keep waiting for. By the end of June we were tracking close to 200 CVEs per day. Using the keyword methodology described here , I found 452 AI-related CVEs this calendar year. If "openclaw" is added to the keyword list, that number jumps by another 536 — a reminder that these counts are sensitive to keyword drift. Given how much the keyword list keeps changing, I'm reconsidering whether to keep publishing this particular metric going forward. KEVs, by contrast, "only" grew 13% — a small April spike aside, it's fairly flat relative to total CVE growth. Networking-gear-related CVEs continued their climb, now accounting for 24% of KEV-related vulnerabilities (up from 20% in Q1) — consistent with the trend I flagged last quarters. As in previous quarters, CVEs from 2024 or earlier still make up about 24% of everything we're tracking. More strikingly, even though the standard enterprise patch cycle is described to run 30–90 days, 181 days into 2026, 46% of today's actively-exploited (KEV) CVEs still trace back to 2025 or earlier. Old vulnerabilities don't retire, new ones keep arriving, and machine-speed vulnerability discovery is going to keep outpacing human-speed patching. Which brings me back — once again — to EPSS as a tool for prioritizing patching against this dataset. If you patched purely by CVSS 9+, you'd be urgently chasing ~3,700 CVEs — but 95% of those sit below 5% EPSS, meaning the real-world odds of exploitation are tiny. Of the 32 CVSS 9+ CVEs with EPSS ≥ 50%, 25 are already on CISA's KEV list. The remaining seven outliers are still high-probability by EPSS but haven't made KEV yet — worth watching. Ray Shoesmith (Mr. Inbetween) once told his therapist, "You know, if I hit somebody, I generally got a pretty good reason." Same principle applies to patching. Don't swing at everything — swing at what you have good reason to believe is coming for you. The one big thing Cisco Talos has discovered "msaRAT," a new Rust-based remote access trojan (RAT) deployed by the Chaos ransomware group. Built on the Tokio asynchronous runtime, it establishes a covert command-and-control (C2) channel by hijacking Chrome or Edge browsers via the Chrome DevTools Protocol (CDP). The infection starts with a deceptive MSI file masquerading as a Windows update that loads the payload directly into memory, paving the way for ransomware deployment. Why do I care? This RAT is a master of evasion, living off the browser to build its C2 infrastructure without ever directly touching the network. By routing traffic through legitimate browser processes and trusted services, msaRAT easily bypasses traditional network-based detections. Additionally, its use of the Tokio runtime enables highly efficient, parallel execution of malicious tasks, accelerating the attacker's ability to establish persistence and deploy doubl…

We’re looking forward to having some great conversations with those of you heading to the desert for Hacker Summer Camp 2026. We have a presence within the Cisco and Splunk booth (2633) during Black Hat where you can chat to us about our latest threat research, incident response, and how Talos powers the Cisco portfolio with our intelligence. Or, feel free to pretend to want to talk to us about those things while grabbing a new multicolored Snorty. That’s fine, too. Here’s some of the ways we’ll be showing up at Black Hat, alongside our friends at Cisco and Splunk: Meet the researchers: Booth lightning talks Our Talosians have spent a lot of time over the last few months putting together some truly... well, enlightening lightning talks. Throughout Wednesday and Thursday at Black Hat, you can expect to see such topics as: Threat actor prompting and the emerging ways adversaries are using prompts, agents, skills, and tools to improve efficiency Warlock ransomware, and why this group does not fit neatly into a simple RaaS or state-linked label. Zero trust for agent identity Building a "second brain" for your second brain Predicting cybersecurity fraud Vulnerability discovery trends ... and much more Lightning talks are 15 minutes. That’s less than 9% of The Odyssey. Don’t worry, we cut the bit where everyone gets turned into Snorty pigs. Talos workshop: When AI finds vulnerabilities faster than humans can patch Date/Time: Wednesday, August 5 | 1:30 p.m. – 3:00 p.m. (Oceanside E, Level 2) If you're looking for something hands-on and interactive, don't miss our workshop with Talos’ Nick Biasini and Cisco’s Omar Santos . In two parts, they’ll demonstrate practical ways security teams can incorporate AI into SOC workflows to identify sophisticated adversary behavior. In Part 1, Omar will discuss the Foundry Security Spec. He’ll walk through how to deploy, build testing harnesses around its core agent roles, and integrate Project CodeGuard so that findings from autonomous testing can be converted into reusable secure-coding rules and future prevention. In Part 2, Nick will demonstrate how Talos leverages AI to transform threat hunting. We will explore best practices for identifying adversarial AI tactics and provide attendees with insights into how Cisco Talos is leveraging AI for defense. Participants will learn how to integrate these defensive AI strategies into their own SOC workflows. Splunk workshop: When agents become insider threats Date/Time: Wednesday, August 5 | 10:15 a.m. – 11:00 a.m. (Mandalay Bay I) The Splunk workshop considers the fact that the next insider threat may not be a person; it may be an autonomous agent using valid credentials and delegated authority. Attendees will see real-world attack paths in which agents move sensitive data across tools, distribute brute-force attempts under a single delegation, and manipulate internal systems without triggering traditional SIEM or UEBA alerts. It was Talos all along One of the questions we hear often is: "How do I buy Talos?" The answer… is that you probably already did. Throughout the Cisco booth you'll see our “ It was Talos all along” campaign, highlighting the fact that Talos isn't a standalone product or a threat intelligence feed you bolt onto your security stack. Talos is already embedded across the Cisco security portfolio, which continually benefits from our threat research and intelligence. To build your curiosity, take a look at our new video, “Where Protection Starts,” to see how Cisco Talos Intelligence Integrations help reduce uncertainty in the SOC: See you in Las Vegas.

In the Linux kernel, the following vulnerability has been resolved: xfs: resample the data fork mapping after cycling ILOCK xfs_reflink_fill_{cow_hole,delalloc} are both presented with an inode, a data fork mapping, and a cow fork mapping. Unfortunately, these two helpers cycle the ILOCK to grab a transaction, which means that the mappings are stale as soon as we reacquire the ILOCK. Currently we refresh the cow fork mapping by re-calling xfs_find_trim_cow_extent, but we don't refresh the data fork mapping beforehand, which means that the xfs_bmap_trim_cow in that function queries the refcount btree about the wrong physical blocks and returns an inaccurate value in *shared. If *shared is now false, the directio write proceeds with a stale data fork mapping. Fix this by querying the data fork mapping if the sequence counter changes across the ILOCK cycle.

# Security Vulnerability Report: STOMP CONNECT Frame Header Injection in Netty ## 1. Vulnerability Summary | Field | Value | |-------|-------| | **Product** | Netty | | **Version** | 4.2.12.Final (and all prior versions with codec-stomp) | | **Component** | `io.netty.handler.codec.stomp.StompSubframeEncoder` | | **Vulnerability Type** | CWE-93: Improper Neutralization of CRLF Sequences / CWE-113: Improper Neutralization of CRLF in HTTP Headers | | **Impact** | STOMP Header Injection / Authentication Bypass | | **CVSS 3.1 Score** | **6.5 (Medium)** | | **CVSS 3.1 Vector** | `CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N` | | **Attack Vector** | Network | | **Attack Complexity** | Low | | **Privileges Required** | Low | | **User Interaction** | None | | **Scope** | Unchanged | | **Confidentiality Impact** | None | | **Integrity Impact** | High | | **Availability Impact** | None | ## 2. Affected Components - `io.netty.handler.codec.stomp.StompSubframeEncoder` — `encodeHeaders()` method (lines 174-200) - `io.netty.handler.codec.stomp.StompSubframeEncoder` — `shouldEscape()` method (lines 214-216) ## 3. Vulnerability Description The Netty STOMP codec encoder (`StompSubframeEncoder`) intentionally skips the `escape()` function for `CONNECT` and `CONNECTED` commands. This means that newline characters (`\n`) in header values of CONNECT frames are written directly to the output, allowing an attacker to inject additional STOMP headers. ### Root Cause In `StompSubframeEncoder.java`, the `shouldEscape()` method (lines 214-216) explicitly excludes CONNECT and CONNECTED commands from escaping: ```java private static boolean shouldEscape(StompCommand command) { return command != StompCommand.CONNECT && command != StompCommand.CONNECTED; } ``` When `shouldEscape()` returns `false`, header values are written without any escaping (line 195): ```java CharSequence headerValue = shouldEscape ? escape(entry.getValue()) : entry.getValue(); ByteBufUtil.writeUtf8(buf, headerValue); // Raw \n written to output buf.writeByte(StompConstants.LF); ``` For other commands (SEND, SUBSCRIBE, etc.), the `escape()` method (lines 218-240) correctly converts `\n` to `\\n`, `\r` to `\\r`, `:` to `\\c`, and `\\` to `\\\\`. ### STOMP Specification Context and Security Analysis The STOMP 1.2 specification (Section 10, Value Encoding) states that CONNECT and CONNECTED frames should **not use escaping**, to maintain backwards compatibility with STOMP 1.0 clients that do not understand escape sequences. **However, "no escaping" does not mean "no validation".** The specification's intent is that CONNECT headers should not use the `\n` → `\\n` escape notation. It does **not** mandate that implementations must accept raw newline characters within header values. There is a critical distinction: - **Escaping** = converting `\n` to `\\n` in the wire format (spec says: don't do this for CONNECT) - **Validation** = rejecting header values that contain `\n` (spec does not prohibit this) Netty's implementation conflates these two concepts: by skipping `escape()`, it also skips **all** protection against newline injection. The correct behavior would be to skip escaping but still **reject** values containing raw newline characters, since such values are inherently malformed — no legitimate STOMP 1.0 or 1.2 header value should contain a raw `\n`. This is analogous to Netty's own SMTP fix (GHSA-jq43-27x9-3v86): SMTP parameters don't need escaping either, but Netty added validation to reject CRLF in parameters. The same principle should apply here. **Additionally**, Netty's own test suite explicitly validates this non-escaping behavior in `StompSubframeEncoderTest.java:126-143` (`testNotEscapeStompHeadersForConnectCommand`), confirming that this is a deliberate design choice — but the test only verifies that escaping is skipped, not that injection is possible. The security implications were not considered. **Summary**: The vulnerability exists because: 1. Header values in CONNECT frames are **neither escaped nor validated** for newlines 2. A raw newline in a header value creates a **new header line** on the wire 3. The STOMP broker parses each line as a separate header 4. The fix should **validate** (reject `\n`) rather than **escape** (convert `\n` to `\\n`), maintaining spec compliance ## 4. Exploitability Prerequisites This vulnerability is exploitable when **all** of the following conditions are met: 1. The application uses Netty's `codec-stomp` module to encode STOMP frames 2. User-controlled input is placed into header values of a `CONNECT` or `CONNECTED` frame 3. The application does **not** perform its own newline sanitization 4. The downstream STOMP broker processes the injected headers (broker-dependent) **Typical affected use cases**: - STOMP proxy/gateway applications that forward or construct CONNECT frames with user-supplied credentials - Web-to-STOMP bridge applications (e.g., WebSocket-STOMP proxies) where login/passcode

When importing connections in Compass it is possible to override some connection options that are otherwise can't be changed via connection form. In particular it is possible to provide a custom browser open command for OIDC auth flow that is usually can be set only globally via Compass settings.