VulnerabilityPublished 15 Aug 2026Updated 6 Nov 2026

CVE-2026-74351: Linux kernel · ocfs2: rebase copied fsdlm LVB pointers in locking_state

Affects Linux kernelSource CVE Database V5

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Not known to be exploited · fixed in e037c1250cc90e7aacb002357d1b0399fc65ecfc : update Linux kernel when convenient.

Data as of 6 Nov 2026, 18:03 UTC

Severity

Medium

Rated Medium by Threat Radar's AI analysis · CVSS not yet scored by NVD

Thin evidence

One scorer or none

Exploitation: No evidence of active exploitation and no public proof of concept
Automatable: Attackers cannot reliably automate steps 1–4 of the kill chain
Technical impact: Limited control over the software or limited information exposure

CISA SSVC assessment, 2026-11-06.

Patch

Available – fixed in e037c1250cc90e7aacb002357d1b0399fc65ecfc, bb44a7690a4d553da705919cf666a80f5ca9011c, 185427b5f7a209254c85c18aad5a4a8e009b2f30 +5

Exploitation evidence

Disclosed: evidence found.
CVE published 15 Aug 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: 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 6 Nov 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.
Weaponized: A Metasploit exploit module or Exploit-DB entry exists (Metasploit scanner modules do not count), 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

Upgrade to a fixed release listed under Affected software.

Affected software

Product	Affected	Fixed in
LinuxLinux	Affected ≥ cf4d8d75d8aba537a19b313a9364fd08ddbd5622, < e037c1250cc90e7aacb002357d1b0399fc65ecfc	Fixed in e037c1250cc90e7aacb002357d1b0399fc65ecfc
LinuxLinux	Affected ≥ cf4d8d75d8aba537a19b313a9364fd08ddbd5622, < bb44a7690a4d553da705919cf666a80f5ca9011c	Fixed in bb44a7690a4d553da705919cf666a80f5ca9011c
LinuxLinux	Affected ≥ cf4d8d75d8aba537a19b313a9364fd08ddbd5622, < 185427b5f7a209254c85c18aad5a4a8e009b2f30	Fixed in 185427b5f7a209254c85c18aad5a4a8e009b2f30
LinuxLinux	Affected ≥ cf4d8d75d8aba537a19b313a9364fd08ddbd5622, < 93612d48fa42b3d1a637eb9279e15281c611c000	Fixed in 93612d48fa42b3d1a637eb9279e15281c611c000
LinuxLinux	Affected ≥ cf4d8d75d8aba537a19b313a9364fd08ddbd5622, < 8614a8f7e81edd34c9f67e454e7024fd12a2a341	Fixed in 8614a8f7e81edd34c9f67e454e7024fd12a2a341
LinuxLinux	Affected ≥ cf4d8d75d8aba537a19b313a9364fd08ddbd5622, < 610a0d2a35496738e1472fb0f318d5008a1c634f	Fixed in 610a0d2a35496738e1472fb0f318d5008a1c634f

AI-suggested

A fix is available in the Linux kernel as indicated by multiple fixed commit versions. Users should update their Linux kernel to a version including the referenced fixes to remediate this vulnerability. No additional mitigation steps are required beyond applying the official patch.

Description

CVE-2026-74351 is a use-after-free vulnerability in the Linux kernel's ocfs2 filesystem locking debug interface. It occurs because a copied pointer to lock value block (LVB) data is not correctly rebased, leading to a stale pointer referencing freed memory during debugfs reads. This can cause kernel memory corruption and potential crashes when debugfs iterates over locking state data.

Impact

The vulnerability can lead to a kernel use-after-free condition causing memory corruption and potential system instability or crashes when debugfs reads locking state information. There is no indication of remote exploitation or privilege escalation from the provided data. The impact is primarily on kernel stability and reliability during debugfs operations related to ocfs2 locking.

Summary

This vulnerability in the Linux kernel's ocfs2 filesystem involves the locking_state debugfs iterator, which copies struct ocfs2_lock_res by value under a lock and later formats that copy for debugfs output. However, the userspace fsdlm stack stores the LVB pointer (sb_lvbptr) which, after the lock is released, still points to the original lockres owner. If the original lockres is freed during this time, the debugfs dump reads from freed memory, causing a use-after-free. The fix rebases the copied sb_lvbptr to point to the copied lock structure, ensuring safe access to the LVB bytes without referencing freed memory. The issue was confirmed by a Kernel Address Sanitizer (KASAN) slab-use-after-free report during ocfs2_dlm_seq_show execution.

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 6 Nov 2026, 18:03 UTC

Technical details

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