VulnerabilityPublished 28 Oct 2026

CVE-2026-99204: Linux kernel · ocfs2/dlm: Protect the recovery list during debugfs reads

Source GCVE Database

Authoritative record:CVE-2026-99204

Not known to be exploited · fixed in 04d4571c00db61a9664f387752fa05cb3c08a537 : update Linux kernel when convenient.

Data as of 28 Oct 2026, 13:30 UTC

Severity

Medium

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

Patch: Available – fixed in 04d4571c00db61a9664f387752fa05cb3c08a537, 4c435828932bf46f29860e4a0375bcae101b778a, 2bc426a32bfb78868c7f76d9547132837b6b5284

Exploitation evidence

Disclosed: evidence found.
CVE published 28 Oct 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.

ghsa-h9q4-gj29-45hp

What to do

Upgrade Linux kernel to 04d4571c00db61a9664f387752fa05cb3c08a537, 4c435828932bf46f29860e4a0375bcae101b778a or 2bc426a32bfb78868c7f76d9547132837b6b5284.

Affected software

Product	Affected	Fixed in
LinuxLinux	Affected ≥ 007dce53a29ccffc000ab5373d188f73881390fd, < 04d4571c00db61a9664f387752fa05cb3c08a537	Fixed in 04d4571c00db61a9664f387752fa05cb3c08a537
LinuxLinux	Affected ≥ 007dce53a29ccffc000ab5373d188f73881390fd, < 4c435828932bf46f29860e4a0375bcae101b778a	Fixed in 4c435828932bf46f29860e4a0375bcae101b778a
LinuxLinux	Affected ≥ 007dce53a29ccffc000ab5373d188f73881390fd, < 2bc426a32bfb78868c7f76d9547132837b6b5284	Fixed in 2bc426a32bfb78868c7f76d9547132837b6b5284
LinuxLinux	Affected =2.6.26	Fixed in–
Red Hatredhat/kernel`pkg:rpm/redhat/kernel`Other threats	Affected =2.6.26	Fixed in–

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

AI-suggested

A fix is available that properly synchronizes access to the recovery participant list by using dlm_reco_state_lock during debugfs reads. Users should apply the updated Linux kernel version containing this patch. No additional mitigation steps are indicated or required beyond applying the official fix.

Description

CVE-2026-99204 is a use-after-free vulnerability in the Linux kernel's OCFS2 Distributed Lock Manager (DLM) debugfs interface. The flaw occurs because the recovery participant list is not properly protected during debugfs reads, allowing concurrent access to freed memory. This issue was detected by Kernel Address Sanitizer (KASAN) and involves improper locking between dlm->spinlock and dlm_reco_state_lock. The vulnerability has been resolved by adding appropriate locking to protect the recovery list during debugfs traversal.

Impact

This vulnerability can lead to use-after-free memory access during debugfs reads of the OCFS2 DLM recovery participant list. Such memory corruption can cause kernel crashes or undefined behavior, potentially impacting system stability. There is no indication of remote exploitability or privilege escalation from the provided data. The issue affects kernel debugging interfaces and is primarily a reliability and stability concern.

References

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