Less than two weeks after the public disclosure of the Copy Fail vulnerability (CVE-2026-31431), another local privilege escalation (LPE) vulnerability in the Linux kernel has been revealed. Referred to as "Dirty Frag," this vulnerability was discovered and reported by Hyunwoo Kim (@v4bel) [1]. In this diary, I will provide a brief background on Dirty Frag, and discuss its relationship to Copy Fail. I will then discuss how to mitigate Dirty Frag and outline recommended next steps for system owners.
Other noteworthy stories that might have slipped under the radar: US gov targets 72-hour patch cycles, malware uses Windows Phone Link to steal OTPs, spy operation targets Eurasian drone industry. The post In Other News: Train Hacker Arrested, PamDOORa Linux Backdoor, New CISA Director Frontrunner appeared first on SecurityWeek .
The persistent, evasive implant provides remote access, surveillance, and credential exfiltration capabilities. The post Sophisticated Quasar Linux RAT Targets Software Developers appeared first on SecurityWeek .
CISA has added the bug to its KEV list, and Microsoft has observed limited exploitation, mainly associated with PoC testing. The post Exploitation of ‘Copy Fail’ Linux Vulnerability Begins appeared first on SecurityWeek .
CVE-2026-31431, known as 'Copy Fail,' is a logic flaw in the Linux kernel's authencesn cryptographic template introduced in 2017. It allows local attackers with code execution privileges to write arbitrary code into the in-memory page cache of other files, including setuid-root binaries, enabling privilege escalation to root. The vulnerability affects all Linux distributions since 2017 and poses a significant risk in multi-tenant and containerized environments where shared kernel memory is used. Exploitation does not modify files on disk but alters their in-memory cached copies, making detection harder. The flaw stems from an optimization that placed page cache pages in a writable scatterlist, allowing out-of-bounds writes during byte rearrangement. Patches have been released that revert this optimization to prevent exploitation.
A race condition in PackageKit allows unprivileged users to escalate privileges when installing packages. The post Easily Exploitable ‘Pack2TheRoot’ Linux Vulnerability Leads to Root Access appeared first on SecurityWeek .
The kernel packages contain the Linux kernel, the core of any Linux operating system.
Security Fix(es):
* kernel: Linux kernel:A use-after-free in bridge multicast in br_multicast_port_ctx_init (CVE-2025-38248)
* kernel: Bluetooth: MGMT: Fix possible UAFs (CVE-2025-39981)
* kernel: mlxsw: spectrum_mr: Fix use-after-free when updating multicast route stats (CVE-2025-68800)
* kernel: Linux kernel: Denial of Service via unsafe requeue in rxrpc_recvmsg (CVE-2026-23066)
* kernel: Linux kernel: Local denial of service and memory leak in DAMON sysfs via setup failure (CVE-2026-23144)
* kernel: Linux kernel: Use-after-free in bonding module can cause system crash or arbitrary code execution (CVE-2026-23171)
* kernel: macvlan: fix error recovery in macvlan_common_newlink() (CVE-2026-23209)
* kernel: net/sched: cls_u32: use skb_header_pointer_careful() (CVE-2026-23204)
* kernel: kernel: Privilege escalation or denial of service via use-after-free in nf_tables_addchain() (CVE-2026-23231)
For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and other related information, refer to the CVE page(s) listed in the References section.
Key Points The Gentlemen RaaS The Gentlemen ransomware‑as‑a‑service (RaaS) operation is a relatively new group that emerged around mid‑2025. The operators advertise their services across multiple underground forums, promoting their ransomware platform and inviting penetration testers (and other technically skilled actors) to join as affiliates. The RaaS provides affiliates with multi‑OS lockers for Windows, Linux, […] The post DFIR Report – The Gentlemen & SystemBC: A Sneak Peek Behind the Proxy appeared first on Check Point Research .
This vulnerability allows local attackers to escalate privileges on affected installations of Linux Kernel. An attacker must first obtain the ability to execute high-privileged code on the target system in order to exploit this vulnerability. The ZDI has assigned a CVSS rating of 7.5. The following CVEs are assigned: CVE-2025-71066.
This vulnerability allows local attackers to escalate privileges on affected installations of Linux Kernel. An attacker must first obtain the ability to execute high-privileged code on the target system in order to exploit this vulnerability. The ZDI has assigned a CVSS rating of 8.2. The following CVEs are assigned: CVE-2026-23092.
Two malicious versions of the popular SDK were uploaded to the PyPI registry, targeting Windows, macOS, and Linux. The post Telnyx Targeted in Growing TeamPCP Supply Chain Attack appeared first on SecurityWeek .
This vulnerability allows local attackers to escalate privileges on affected installations of Red Hat Enterprise Linux. An attacker must first obtain the ability to execute low-privileged code on the target system in order to exploit this vulnerability. The ZDI has assigned a CVSS rating of 8.8. The following CVEs are assigned: CVE-2025-40277.
In the Linux kernel, the following vulnerability has been resolved: macvlan: observe an RCU grace period in macvlan_common_newlink() error path valis reported that a race condition still happens after my prior patch. macvlan_common_newlink() might have made @dev visible before detecting an error, and its caller will directly call free_netdev(dev). We must respect an RCU period, either in macvlan or the core networking stack. After adding a temporary mdelay(1000) in macvlan_forward_source_one() to open the race window, valis repro was: ip link add p1 type veth peer p2 ip link set address 00:00:00:00:00:20 dev p1 ip link set up dev p1 ip link set up dev p2 ip link add mv0 link p2 type macvlan mode source (ip link add invalid% link p2 type macvlan mode source macaddr add 00:00:00:00:00:20 &) ; sleep 0.5 ; ping -c1 -I p1 1.2.3.4 PING 1.2.3.4 (1.2.3.4): 56 data bytes RTNETLINK answers: Invalid argument BUG: KASAN: slab-use-after-free in macvlan_forward_source (drivers/net/macvlan.c:408 drivers/net/macvlan.c:444) Read of size 8 at addr ffff888016bb89c0 by task e/175 CPU: 1 UID: 1000 PID: 175 Comm: e Not tainted 6.19.0-rc8+ #33 NONE Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.14.0-2 04/01/2014 Call Trace: <IRQ> dump_stack_lvl (lib/dump_stack.c:123) print_report (mm/kasan/report.c:379 mm/kasan/report.c:482) ? macvlan_forward_source (drivers/net/macvlan.c:408 drivers/net/macvlan.c:444) kasan_report (mm/kasan/report.c:597) ? macvlan_forward_source (drivers/net/macvlan.c:408 drivers/net/macvlan.c:444) macvlan_forward_source (drivers/net/macvlan.c:408 drivers/net/macvlan.c:444) ? tasklet_init (kernel/softirq.c:983) macvlan_handle_frame (drivers/net/macvlan.c:501) Allocated by task 169: kasan_save_stack (mm/kasan/common.c:58) kasan_save_track (./arch/x86/include/asm/current.h:25 mm/kasan/common.c:70 mm/kasan/common.c:79) __kasan_kmalloc (mm/kasan/common.c:419) __kvmalloc_node_noprof (./include/linux/kasan.h:263 mm/slub.c:5657 mm/slub.c:7140) alloc_netdev_mqs (net/core/dev.c:12012) rtnl_create_link (net/core/rtnetlink.c:3648) rtnl_newlink (net/core/rtnetlink.c:3830 net/core/rtnetlink.c:3957 net/core/rtnetlink.c:4072) rtnetlink_rcv_msg (net/core/rtnetlink.c:6958) netlink_rcv_skb (net/netlink/af_netlink.c:2550) netlink_unicast (net/netlink/af_netlink.c:1319 net/netlink/af_netlink.c:1344) netlink_sendmsg (net/netlink/af_netlink.c:1894) __sys_sendto (net/socket.c:727 net/socket.c:742 net/socket.c:2206) __x64_sys_sendto (net/socket.c:2209) do_syscall_64 (arch/x86/entry/syscall_64.c:63 arch/x86/entry/syscall_64.c:94) entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:131) Freed by task 169: kasan_save_stack (mm/kasan/common.c:58) kasan_save_track (./arch/x86/include/asm/current.h:25 mm/kasan/common.c:70 mm/kasan/common.c:79) kasan_save_free_info (mm/kasan/generic.c:587) __kasan_slab_free (mm/kasan/common.c:287) kfree (mm/slub.c:6674 mm/slub.c:6882) rtnl_newlink (net/core/rtnetlink.c:3845 net/core/rtnetlink.c:3957 net/core/rtnetlink.c:4072) rtnetlink_rcv_msg (net/core/rtnetlink.c:6958) netlink_rcv_skb (net/netlink/af_netlink.c:2550) netlink_unicast (net/netlink/af_netlink.c:1319 net/netlink/af_netlink.c:1344) netlink_sendmsg (net/netlink/af_netlink.c:1894) __sys_sendto (net/socket.c:727 net/socket.c:742 net/socket.c:2206) __x64_sys_sendto (net/socket.c:2209) do_syscall_64 (arch/x86/entry/syscall_64.c:63 arch/x86/entry/syscall_64.c:94) entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:131)
Other noteworthy stories that might have slipped under the radar: Telus Digital data breach, vulnerabilities in Linux AppArmor allow root privileges, US defense contractor behind Coruna exploits. The post In Other News: N8n Flaw Exploited, Slopoly Malware, Interpol Cybercrime Crackdown appeared first on SecurityWeek .
A use-after-free vulnerability (CVE-2026-23074) in the Linux kernel's teql queueing discipline can lead to privilege escalation on Container-Optimized OS nodes. This vulnerability affects certain versions of Red Hat Enterprise Linux 6 Extended Lifecycle Support and specific Google Kubernetes Engine (GKE) node pool versions. GKE Standard clusters are impacted, while GKE Autopilot clusters are not affected by default unless specific insecure configurations are used. GKE Sandbox clusters and bare metal GDC software are not affected. Patch versions are available for affected GKE Ubuntu node pools and Container-Optimized OS node pools. Red Hat has released kernel updates for affected Red Hat Enterprise Linux 6 Extended Lifecycle Support versions. Bare metal GDC software does not require action as it is not affected.
A malicious npm package named "ambar-src" reached 50,000 downloads in days before being removed from the registry. It uses a preinstall script to execute malicious code during installation, targeting Windows, Linux, and macOS systems. The package employs detection evasion techniques and deploys powerful open-source malware variants. It abuses npm's preinstall script hook to trigger the payload without explicit invocation. The malware fetches additional payloads from remote servers and uses Yandex Cloud for command and control. Affected systems should be considered fully compromised, requiring immediate incident response actions. The attack highlights the speed at which supply chain risks can propagate and confirms that npm install is a high-risk action.
LockBit 5.0, the latest version of the notorious ransomware, has been released with support for Windows, Linux, and ESXi systems. This update brings improved defense evasion, faster encryption, and enhanced modularity. The Windows variant employs extensive anti-analysis techniques, while Linux and ESXi versions remain unpacked. All variants share a common encryption scheme using XChaCha20 and Curve25519. LockBit 5.0 demonstrates a focus on enterprise and infrastructure targets, including explicit support for Proxmox virtualization. The group's data leak site reveals a primary focus on the U.S.business sector, with victims spanning various industries. LockBit's infrastructure has shown connections to SmokeLoader, suggesting possible cooperation or infrastructure reuse among malware operators.
WSL or “Windows Subsystem Linux”[1] is a feature in the Microsoft Windows ecosystem that allows users to run a real Linux environment directly inside Windows without needing a traditional virtual machine or dual boot setup. The latest version, WSL2, runs a lightweight virtualized Linux kernel for better compatibility and performance, making it especially useful for development, DevOps, and cybersecurity workflows where Linux tooling is essential but Windows remains the primary operating system. It was introduced a few years ago (2016) as part of Windows 10.
