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VulnerabilityPublished Updated

CVE-2026-45966: Linux kernel · apparmor: fix NULL pointer dereference in __unix_needs_revalidation

Affects Linux kernelSource GCVE Database

0

Not known to be exploited · CVSS 5.5 Medium · fixed in 6.17.0-1017.17~24.04.1 : update Linux kernel when convenient.

Data as of 26 Oct 2026, 12:55 UTC

CVSS 3.1 base score
5.5Medium
How severe the flaw is on the 0–10 CVSS scale.
EPSS
0.1% chance of exploitation in 30 days – higher than 1% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch
Available – fixed in 6.17.0-1017.17~24.04.1, 6.17.0-1015.15~24.04.1, 6.17.0-1018.19~24.04.1 +13
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Exploitation evidence

  1. Disclosed: evidence found.

    CVE published 27 May 2026

  2. Detectable: no evidence on record.

    No public nuclei template indexed

  3. Weaponised: no evidence on record.

    No public exploit code indexed in Metasploit or Exploit-DB

  4. Exploited in the wild: no evidence on record.

    Not in CISA KEV and no source reports exploitation

  5. Observed by OffSeq 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.

What to do

Upgrade to a fixed release listed under Affected software.

Affected software

ProductAffectedFixed in
Ubuntu 26.04 LTSlinux-azure-fdepkg:deb/ubuntu/linux-azure-fde?arch=source&distro=resoluteOther threatsAffected
  • 7.0.0-1003.3 – 7.0.0-1009.9
5 affected builds
Fixed in–
Ubuntu 25.10linuxpkg:deb/ubuntu/linux?arch=source&distro=questingOther threatsAffected
  • <6.17.0-29.29
Fixed in
  • 6.17.0-29.29
Ubuntu 25.10linux-awspkg:deb/ubuntu/linux-aws?arch=source&distro=questingOther threatsAffected
  • <6.17.0-1015.15
Fixed in
  • 6.17.0-1015.15
Ubuntu 25.10linux-azurepkg:deb/ubuntu/linux-azure?arch=source&distro=questingOther threatsAffected
  • <6.17.0-1015.15
Fixed in
  • 6.17.0-1015.15
Ubuntu 25.10linux-azure-fdepkg:deb/ubuntu/linux-azure-fde?arch=source&distro=questingOther threatsAffected
  • 6.17.0-1003.3 – 6.17.0-1017.17
10 affected builds
Fixed in–
Ubuntu 25.10linux-gcppkg:deb/ubuntu/linux-gcp?arch=source&distro=questingOther threatsAffected
  • <6.17.0-1018.19
Fixed in
  • 6.17.0-1018.19

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

AI-suggested

An official patch is available and should be applied to affected Linux kernel versions. The vendor advisory from Ubuntu confirms the fix. Users should update to patched kernel versions to prevent kernel crashes caused by this NULL pointer dereference. No additional mitigation is required beyond applying the official fix.

Description

A NULL pointer dereference vulnerability in the Linux kernel's AppArmor module was fixed. The issue occurs in the __unix_needs_revalidation() function when receiving file descriptors via SCM_RIGHTS, where socket pointers can be NULL, causing kernel crashes. This regression was introduced in AppArmor 5.0.0 (kernel 6.17+). The crash leads to a kernel NULL pointer dereference and system instability. A patch is available to add proper NULL checks preventing this issue.

References

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