CVE-2026-45966: Linux kernel · apparmor: fix NULL pointer dereference in __unix_needs_revalidation
Affects Linux kernelSource GCVE Database
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
- 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:HExploitation evidence
Disclosed: evidence found.
CVE published 27 May 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.
What to do
Upgrade to a fixed release listed under Affected software.
Patches and advisories
Affected software
| Product | Affected | Fixed in |
|---|---|---|
Ubuntu 26.04 LTSlinux-azure-fdepkg:deb/ubuntu/linux-azure-fde?arch=source&distro=resoluteOther threats | Affected
| Fixed in– |
Ubuntu 25.10linuxpkg:deb/ubuntu/linux?arch=source&distro=questingOther threats | Affected
| Fixed in
|
Ubuntu 25.10linux-awspkg:deb/ubuntu/linux-aws?arch=source&distro=questingOther threats | Affected
| Fixed in
|
Ubuntu 25.10linux-azurepkg:deb/ubuntu/linux-azure?arch=source&distro=questingOther threats | Affected
| Fixed in
|
Ubuntu 25.10linux-azure-fdepkg:deb/ubuntu/linux-azure-fde?arch=source&distro=questingOther threats | Affected
| Fixed in– |
Ubuntu 25.10linux-gcppkg:deb/ubuntu/linux-gcp?arch=source&distro=questingOther threats | Affected
| Fixed in
|
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
- ubuntu.com/security/CVE-2026-45966 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-45966 (opens in a new tab)
- git.kernel.org/linus/e2938ad00b21340c0362562dfedd7cfec0554d67 (opens in a new tab)
- ubuntu.com/security/notices/USN-8374-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8508-1 (opens in a new tab)