VulnerabilityPublished 3 Nov 2026Updated 4 Nov 2026

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

Affects Linux kernelSource GCVE Database

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Authoritative record:CVE-2026-99222· High

Not known to be exploited.

Data as of 5 Nov 2026, 00:01 UTC

Severity

High

Rated by Threat Radar · CVSS not yet scored by NVD

Thin evidence

One scorer or none

EPSS: 0.1% chance of exploitation in 30 days – higher than 7% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.

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 4 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

Affected software

Product	Affected	Fixed in
Ubuntu 26.10linux`pkg:deb/ubuntu/linux?arch=source&distro=stonking`Other threats	Affected 7.0.0-14.14 – 7.3.0-10.10 7 affected builds	Fixed in–
Ubuntu 26.10linux-aws`pkg:deb/ubuntu/linux-aws?arch=source&distro=stonking`Other threats	Affected 7.0.0-1004.4 – 7.3.0-1004.4 6 affected builds	Fixed in–
Ubuntu 26.10linux-azure`pkg:deb/ubuntu/linux-azure?arch=source&distro=stonking`Other threats	Affected 7.0.0-1004.4 – 7.3.0-1004.4 6 affected builds	Fixed in–
Ubuntu 26.10linux-azure-fde`pkg:deb/ubuntu/linux-azure-fde?arch=source&distro=stonking`Other threats	Affected 7.0.0-1004.4 – 7.3.0-1004.5 4 affected builds	Fixed in–
Ubuntu 26.10linux-gcp`pkg:deb/ubuntu/linux-gcp?arch=source&distro=stonking`Other threats	Affected 7.0.0-1003.3 – 7.3.0-1004.4 6 affected builds	Fixed in–
Ubuntu 26.10linux-oracle`pkg:deb/ubuntu/linux-oracle?arch=source&distro=stonking`Other threats	Affected 7.0.0-1003.3 – 7.3.0-1004.4 6 affected builds	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 for this vulnerability is available and should be applied by updating to patched Linux kernel versions that include the corrected keyctl_read_key() implementation. The fix moves the read method check inside the semaphore-protected critical section, preventing use-after-free conditions. Users should upgrade to fixed kernel versions listed in the affectedVersions field. No additional mitigations are necessary once the patch is applied.

Description

CVE-2026-99222 is a vulnerability in the Linux kernel's key management subsystem where the read method check is not properly synchronized against type removal. This flaw allows a key's read method to be accessed after its module has been unloaded, potentially reading freed module memory. The issue arises because the keyctl_read_key() function checks key->type->read without holding the key semaphore, allowing a race condition during module unload and garbage collection. The vulnerability has been resolved by moving the method check inside the critical section protected by the semaphore and returning an error when the read method is not supported.

Impact

Exploitation of this vulnerability could allow reading of freed module memory, potentially leading to information disclosure or kernel memory corruption. However, the vulnerability requires specific conditions involving module unloading and key usage, limiting its practical exploitation. No known exploits are reported in the wild. The severity is assessed as medium due to the potential for memory access issues but limited attack surface.

Summary

The Linux kernel's keyctl_read_key() function previously checked the key type's read method outside the protection of the key semaphore (key->sem). This allowed a race condition where a key's type could be removed (module unloaded) after the check but before the read invocation, leading to use-after-free of module memory. The vulnerability specifically affects RxRPC keys during unloading of the AF_RXRPC module. The fix involves moving the read method check inside the critical section protected by key->sem, ensuring the key type cannot be unregistered until the semaphore is released. Additionally, the function now returns -EOPNOTSUPP if the key type has no read method, preventing invalid reads.

GCVE source: db.gcve.eu
OSV ID: UBUNTU-CVE-2026-99222
Osv Schema Version: 1.7.0
Ecosystems: Ubuntu:Pro:14.04:LTS, Ubuntu:Pro:16.04:LTS, Ubuntu: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:Realtime:22.04:LTS, Ubuntu:Pro:FIPS-preview:22.04:LTS, Ubuntu:Pro:FIPS-updates:22.04:LTS, Ubuntu:24.04:LTS, Ubuntu:Nvidia-BlueField:24.04:LTS, Ubuntu:Pro:Realtime:24.04:LTS, Ubuntu:Pro:FIPS-updates:24.04:LTS, Ubuntu:26.10, Ubuntu:26.04:LTS

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 4 Nov 2026, 21:24 UTC

Technical details

References

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