VulnerabilityPublished 15 Aug 2026Updated 6 Nov 2026

CVE-2026-74348: Linux kernel · ocfs2/dlm: require a ref for locking_state debugfs open

Affects Linux kernelSource CVE Database V5

Compare

Not known to be exploited · fixed in aa7883b6a3c76301a3299deb34de948e73bb6a08 : patch Linux kernel soon.

Data as of 6 Nov 2026, 18:03 UTC

Severity

High

Rated High 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 aa7883b6a3c76301a3299deb34de948e73bb6a08, a09831214912a1f270663d935613910fafd8d883, a087b2d3411e7f9df71ba3293596923ee2c70d65 +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 ≥ 4e3d24ed1a1285fe3289653aacc965642706bacb, < aa7883b6a3c76301a3299deb34de948e73bb6a08	Fixed in aa7883b6a3c76301a3299deb34de948e73bb6a08
LinuxLinux	Affected ≥ 4e3d24ed1a1285fe3289653aacc965642706bacb, < a09831214912a1f270663d935613910fafd8d883	Fixed in a09831214912a1f270663d935613910fafd8d883
LinuxLinux	Affected ≥ 4e3d24ed1a1285fe3289653aacc965642706bacb, < a087b2d3411e7f9df71ba3293596923ee2c70d65	Fixed in a087b2d3411e7f9df71ba3293596923ee2c70d65
LinuxLinux	Affected ≥ 4e3d24ed1a1285fe3289653aacc965642706bacb, < 90a6512425414098a63fc97b77bed089c75d106b	Fixed in 90a6512425414098a63fc97b77bed089c75d106b
LinuxLinux	Affected ≥ 4e3d24ed1a1285fe3289653aacc965642706bacb, < 9c81c1a61a52b6ecf0d14f1dbd95f154a7a9e92a	Fixed in 9c81c1a61a52b6ecf0d14f1dbd95f154a7a9e92a
LinuxLinux	Affected ≥ 4e3d24ed1a1285fe3289653aacc965642706bacb, < 6cc93dea4078cbcddee63fa2234e382a76600464	Fixed in 6cc93dea4078cbcddee63fa2234e382a76600464

AI-suggested

A fix is available in the Linux kernel as indicated by multiple fixed commit versions. Users should update to a kernel version that includes these fixes to prevent this use-after-free vulnerability. No additional mitigation steps are required beyond applying the official patch.

Description

A use-after-free vulnerability exists in the Linux kernel's ocfs2/dlm locking_state debugfs interface. The issue occurs because the open operation does not properly handle the failure of acquiring a reference to the dlm context, leading to a stale pointer being stored and later freed memory being accessed during release. This flaw can cause kernel memory corruption detected by KASAN.

Impact

This vulnerability can lead to use-after-free conditions in kernel memory, potentially causing kernel crashes or memory corruption. It is detected by KASAN during testing, indicating a serious memory safety issue in the kernel's distributed lock manager debug interface. There is no indication of exploitation in the wild.

Summary

The vulnerability in the Linux kernel's ocfs2/dlm subsystem involves debug_lockres_open() improperly handling the return value of dlm_grab(). When the last domain unregister removes the context, dlm_grab() returns NULL, but open still stores the raw pointer and returns success. Later, debug_lockres_release() calls dlm_put() on a freed context, causing a slab-use-after-free error detected by KASAN. The fix involves failing the open operation when dlm_grab() cannot acquire a reference and cleaning up the seq_file private state to prevent handing out a file descriptor without ownership of the dlm_ctxt.

References

Community reviews

Loading reviews…

Exploitation evidence

What to do

Affected software

Description

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

Technical details

References

Community reviews

Related threats