CVE-2026-89600: Linux kernel · fanotify: fix use-after-free of file range info
Affects Linux kernelSource GCVE Database
Not known to be exploited · CVSS 7.8 High.
Data as of 26 Oct 2026, 17:16 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 addresses the use-after-free by changing how the file range position is stored in permission events. Users should update to patched versions of the Linux kernel listed as affected. Since this is a kernel-level vulnerability, applying the official kernel updates from the vendor or distribution is the recommended remediation.
Description
A use-after-free vulnerability in the Linux kernel's fanotify subsystem was resolved. The flaw involved improper handling of file range information in permission events, leading to stale pointer dereference and potential memory corruption. This issue was fixed by storing the range position directly in the permission event and avoiding reliance on the triggering task's stack. The vulnerability affects specific Linux kernel versions listed and has a CVSS score of 7.8, indicating a high impact on confidentiality, integrity, and availability.
References
- nvd.nist.gov/vuln/detail/CVE-2026-89600 (opens in a new tab)
- git.kernel.org/stable/c/66aa9a9e6481bfa512ee5b6380eaaec455a954d2 (opens in a new tab)
- git.kernel.org/stable/c/b8f73b163b646bc56d4dce9c697a578e333f4894 (opens in a new tab)
- git.kernel.org/stable/c/d7f1cf5be33ef0175a4e8ed8687aeb98fb00a851 (opens in a new tab)
- ubuntu.com/security/CVE-2026-89600 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-89600 (opens in a new tab)
- git.kernel.org/linus/d7f1cf5be33ef0175a4e8ed8687aeb98fb00a851 (opens in a new tab)