VulnerabilityPublished 24 Jun 2026Updated 7 Sep 2026

CVE-2026-52995: Linux kernel · net/rds: zero per-item info buffer before handing it to visitors

Affects Linux kernelSource GCVE Database

Not known to be exploited · CVSS 5.5 Medium · patch available : update Linux kernel when convenient.

Data as of 26 Oct 2026, 14:05 UTC

CVSS 3.1 base score

5.5Medium

How severe the flaw is on the 0–10 CVSS scale.

EPSS: 0.1% chance of exploitation in 30 days – higher than 2% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch: Available

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Attack Vector: Local
Attack Complexity: Low
Privileges Required: Low
User Interaction: None
Scope: Unchanged
Confidentiality: None
Integrity: None
Availability: High

Bold values are the worst case: easiest to exploit or largest impact.

Attack Vector: Local: The vulnerable component is not bound to the network stack and the attacker’s path is via read/write/execute capabilities. Either: the attacker exploits the vulnerability by accessing the target system locally (e.g., keyboard, console), or remotely (e.g., SSH); or the attacker relies on User Interaction by another person to perform actions required to exploit the vulnerability (e.g., tricking a legitimate user into opening a malicious document).
Attack Complexity: Low: Specialized access conditions or extenuating circumstances do not exist. An attacker can expect repeatable success against the vulnerable component.
Privileges Required: Low: The attacker is authorized with (i.e., requires) privileges that provide basic user capabilities that could normally affect only settings and files owned by a user. Alternatively, an attacker with Low privileges may have the ability to cause an impact only to non-sensitive resources.
User Interaction: None: The vulnerable system can be exploited without any interaction from any user.
Scope: Unchanged: An exploited vulnerability can only affect resources managed by the same security authority. In this case, the vulnerable component and the impacted component are either the same, or both are managed by the same security authority.
Confidentiality: None: There is no loss of confidentiality within the impacted component.
Integrity: None: There is no loss of integrity within the impacted component.
Availability: High: There is total loss of availability, resulting in the attacker being able to fully deny access to resources in the impacted component; this loss is either sustained (while the attacker continues to deliver the attack) or persistent (the condition persists even after the attack has completed). Alternatively, the attacker has the ability to deny some availability, but the loss of availability presents a direct, serious consequence to the impacted component (e.g., the attacker cannot disrupt existing connections, but can prevent new connections; the attacker can repeatedly exploit a vulnerability that, in each instance of a successful attack, leaks a only small amount of memory, but after repeated exploitation causes a service to become completely unavailable).

Definitions: FIRST CVSS v3.1 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 24 Jun 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponised: Public exploit code exists in Metasploit or Exploit-DB, or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

Affected software

Product	Affected	Fixed in
Ubuntu 26.04 LTSlinux`pkg:deb/ubuntu/linux@7.0.0-28.28?arch=source&distro=resolute`Other threats	Affected 6.17.0-5.5 – 7.0.0-28.28 18 affected builds	Fixed in–
Ubuntu 26.04 LTSlinux-aws`pkg:deb/ubuntu/linux-aws@7.0.0-1008.8?arch=source&distro=resolute`Other threats	Affected 6.17.0-1002.2 – 7.0.0-1008.8 9 affected builds	Fixed in–
Ubuntu 26.04 LTSlinux-azure`pkg:deb/ubuntu/linux-azure@7.0.0-1009.9?arch=source&distro=resolute`Other threats	Affected 6.17.0-1003.3 – 7.0.0-1009.9 10 affected builds	Fixed in–
Ubuntu 26.04 LTSlinux-azure-fde`pkg:deb/ubuntu/linux-azure-fde@7.0.0-1008.8?arch=source&distro=resolute`Other threats	Affected 7.0.0-1003.3 – 7.0.0-1008.8 4 affected builds	Fixed in–
Ubuntu 26.04 LTSlinux-gcp`pkg:deb/ubuntu/linux-gcp@7.0.0-1008.8?arch=source&distro=resolute`Other threats	Affected 6.17.0-1002.2 – 7.0.0-1008.8 9 affected builds	Fixed in–
Ubuntu 26.04 LTSlinux-gke`pkg:deb/ubuntu/linux-gke@7.0.0-1003.4?arch=source&distro=resolute`Other threats	Affected =7.0.0-1002.3 =7.0.0-1003.4	Fixed in–

Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.

Description

In the Linux kernel, the following vulnerability has been resolved: net/rds: zero per-item info buffer before handing it to visitors rds_for_each_conn_info() and rds_walk_conn_path_info() both hand a caller-allocated on-stack u64 buffer to a per-connection visitor and then copy the full item_len bytes back to user space via rds_info_copy() regardless of how much of the buffer the visitor actually wrote. rds_ib_conn_info_visitor() and rds6_ib_conn_info_visitor() only write a subset of their output struct when the underlying rds_connection is not in state RDS_CONN_UP (src/dst addr, tos, sl and the two GIDs via explicit memsets). Several u32 fields (max_send_wr, max_recv_wr, max_send_sge, rdma_mr_max, rdma_mr_size, cache_allocs) and the 2-byte alignment hole between sl and cache_allocs remain as whatever stack contents preceded the visitor call and are then memcpy_to_user()'d out to user space. struct rds_info_rdma_connection and struct rds6_info_rdma_connection are the only rds_info_* structs in include/uapi/linux/rds.h that are not marked __attribute__((packed)), so they have a real alignment hole. The other info visitors (rds_conn_info_visitor, rds6_conn_info_visitor, rds_tcp_tc_info, ...) write all fields of their packed output struct today and are not known to be vulnerable, but a future visitor that adds a conditional write-path would have the same bug. Reproduction on a kernel built without CONFIG_INIT_STACK_ALL_ZERO=y: a local unprivileged user opens AF_RDS, sets SO_RDS_TRANSPORT=IB, binds to a local address on an RDMA-capable netdev (rxe soft-RoCE on any netdev is sufficient), sendto()'s any peer on the same subnet (fails cleanly but installs an rds_connection in the global hash in RDS_CONN_CONNECTING), then calls getsockopt(SOL_RDS, RDS_INFO_IB_CONNECTIONS). The returned 68-byte item contains 26 bytes of stack garbage including kernel text/data pointers: 0..7 0a 63 00 01 0a 63 00 02 src=10.99.0.1 dst=10.99.0.2 8..39 00 ... gids (memset-zeroed) 40..47 e0 92 a3 81 ff ff ff ff kernel pointer (max_send_wr) 48..55 7f 37 b5 81 ff ff ff ff kernel pointer (rdma_mr_max) 56..59 01 00 08 00 rdma_mr_size (garbage) 60..61 00 00 tos, sl 62..63 00 00 alignment padding 64..67 18 00 00 00 cache_allocs (garbage) Fix by zeroing the per-item buffer in both rds_for_each_conn_info() and rds_walk_conn_path_info() before invoking the visitor. This covers the IPv4/IPv6 IB visitors and hardens all current and future visitors against the same class of bug. No functional change for visitors that fully populate their output. Changes in v2: - retarget at the net tree (subject prefix "[PATCH net v2]", net/rds: prefix in the title) - pick up Reviewed-by tags from Sharath Srinivasan and Allison Henderson

GCVE source: db.gcve.eu
OSV ID: UBUNTU-CVE-2026-52995
Osv Schema Version: 1.7.0
Ecosystems: Ubuntu:Pro:14.04:LTS, Ubuntu:Pro:16.04:LTS, Ubuntu:16.04:LTS, Ubuntu:Pro:FIPS:16.04:LTS, Ubuntu:Pro:18.04:LTS, Ubuntu:18.04:LTS, Ubuntu:Pro:FIPS-updates:18.04:LTS, Ubuntu:Pro:FIPS:18.04:LTS, Ubuntu:Pro:20.04:LTS, Ubuntu:20.04:LTS, Ubuntu:Pro:FIPS-updates:20.04:LTS, Ubuntu:Pro:FIPS:20.04:LTS, Ubuntu:22.04:LTS, Ubuntu:Nvidia-BlueField:22.04:LTS, Ubuntu:Pro:FIPS-preview:22.04:LTS, Ubuntu:Pro:FIPS-updates:22.04:LTS, Ubuntu:Pro:Realtime:22.04:LTS, Ubuntu:24.04:LTS, Ubuntu:Nvidia-BlueField:24.04:LTS, Ubuntu:Pro:FIPS-updates:24.04:LTS, Ubuntu:Pro:Realtime:24.04:LTS, Ubuntu:25.10, Ubuntu:26.04:LTS
CVSS version: 3.1

References

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