CVE-2026-89762: Linux kernel · apparmor: fix cred UAF caused by begin_current_label_crit_section()
Affects Linux kernelSource GCVE Database
Not known to be exploited · CVSS 7.8 High.
Data as of 26 Oct 2026, 14:05 UTC
- EPSS
- 0.1% chance of exploitation in 30 days – higher than 2% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:HExploitation evidence
Disclosed: evidence found.
CVE published 11 Sep 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
Affected software
| Product | Affected | Fixed in |
|---|---|---|
Ubuntu 26.04 LTSlinuxpkg:deb/ubuntu/linux?arch=source&distro=resoluteOther threats | Affected
| Fixed in– |
Ubuntu 26.04 LTSlinux-awspkg:deb/ubuntu/linux-aws?arch=source&distro=resoluteOther threats | Affected
| Fixed in– |
Ubuntu 26.04 LTSlinux-azurepkg:deb/ubuntu/linux-azure?arch=source&distro=resoluteOther threats | Affected
| Fixed in– |
Ubuntu 26.04 LTSlinux-azure-fdepkg:deb/ubuntu/linux-azure-fde?arch=source&distro=resoluteOther threats | Affected
| Fixed in– |
Ubuntu 26.04 LTSlinux-gcppkg:deb/ubuntu/linux-gcp?arch=source&distro=resoluteOther threats | Affected
| Fixed in– |
Ubuntu 26.04 LTSlinux-gkepkg:deb/ubuntu/linux-gke?arch=source&distro=resoluteOther 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
A fix is available that changes the timing of credential replacement in AppArmor to occur via task_work at the end of the current syscall, preventing use-after-free conditions. Users should apply the official Linux kernel updates that include this patch. Since this is a kernel vulnerability, upgrading to a patched kernel version is the recommended remediation. No additional mitigations are indicated by the vendor advisory.
Description
A use-after-free (UAF) vulnerability in the Linux kernel's AppArmor security module was resolved. The issue arises from improper handling of credential (cred) references during label replacement in AppArmor's begin_current_label_crit_section() function. This can cause the task's real credentials pointer to reference freed memory, leading to UAF when accessing current credentials. The vulnerability was fixed by deferring credential replacement via task_work to the end of the current syscall, preventing premature freeing of credentials.
References
- nvd.nist.gov/vuln/detail/CVE-2026-89762 (opens in a new tab)
- git.kernel.org/stable/c/361488984d668235438faac28635f3632351407f (opens in a new tab)
- git.kernel.org/stable/c/3f4ae5fab613dca01d6a2a8210dd832e009fcf47 (opens in a new tab)
- git.kernel.org/stable/c/580f777d6d9fd07fc034bd1aeba5c30fd48871a2 (opens in a new tab)
- git.kernel.org/stable/c/587a6a92b93ec314c583bbf747413af170d42540 (opens in a new tab)
- ubuntu.com/security/CVE-2026-89762 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-89762 (opens in a new tab)
- git.kernel.org/linus/3f4ae5fab613dca01d6a2a8210dd832e009fcf47 (opens in a new tab)