VulnerabilityPublished 2 Nov 2026

CVE-2026-99222: Linux kernel · keys: Protect the read method check against type removal

Affects Linux kernelSource CVE Database V5

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Not known to be exploited · fixed in ff44f1b303aa76a818d898e85c56ed4852c031e2 : patch Linux kernel soon.

Data as of 2 Nov 2026, 16:32 UTC

Severity

High

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

Thin evidence

One scorer or none

Patch: Available – fixed in ff44f1b303aa76a818d898e85c56ed4852c031e2, ff11cfed85cbfdd7fe1185ebd18d2c7a8353ad8d, e5f830ae6611cddbfc504c43f14155f60b63206a +9

Exploitation evidence

Disclosed: evidence found.
CVE published 2 Nov 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 2 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 >=4.14.177 <4.15 >=4.19.118 <4.20 >=5.4.35 <5.5 >=5.6.7 <5.7	Fixed in ff44f1b303aa76a818d898e85c56ed4852c031e2 ff11cfed85cbfdd7fe1185ebd18d2c7a8353ad8d e5f830ae6611cddbfc504c43f14155f60b63206a e2a2deda08d91644f5e30c17d267b1cdc5f124b2 cf1af7df80e38bf58bd74c2cccce32fcbd1a596a 1486caee47b4909f52835a957c3293e970113e44 6a36e2a1a017c51f8a8ad2a094566bad97c46a9b 5.7 5.5 4.20 4.15 3edc064069d07e7d37359fcb4d03d3bab15ee3ab
LinuxLinux	Affected =5.7	Fixed in–

AI-suggested

This vulnerability has been fixed in Linux kernel versions 4.20, 5.5, 5.7, and corresponding commits. Users and administrators should upgrade to these fixed versions or later to mitigate the issue. No additional mitigation steps are required beyond applying the official patches.

Description

A vulnerability in the Linux kernel keys subsystem allowed a race condition where the read method check could be performed on a key type that was being removed, potentially leading to reading freed module memory. This was due to the check occurring outside a semaphore-protected critical section. The issue was fixed by moving the method check inside the critical section, preventing use-after-free scenarios during module unload.

Impact

The vulnerability could allow a read operation on a key type whose module is concurrently being unloaded, potentially causing access to freed memory. This could lead to kernel memory corruption or instability. However, no known exploits in the wild have been reported. The impact is limited to kernel memory safety and module unloading race conditions.

Summary

CVE-2026-99222 addresses a flaw in the Linux kernel's keyctl_read_key() function where the check of key->type->read was performed without holding the key semaphore (key->sem). Although a reference keeps the key alive, it does not pin the module containing its type, allowing a surviving RxRPC key to be read while the AF_RXRPC module is being unloaded. This could lead to reading freed module storage. The fix moves the method check inside the critical section protected by key->sem, ensuring the key type cannot be unregistered or retyped until the semaphore is released. Additionally, the function now returns -EOPNOTSUPP if the type has no read method, with temporary buffer allocation handled safely outside the semaphore.

References

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 2 Nov 2026, 16:32 UTC

Technical details

References

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