CVE-2026-64425: Linux kernel · io_uring/io-wq: re-check IO_WQ_BIT_EXIT for each linked work item
Affects Linux kernelSource GCVE Database
Not known to be exploited · CVSS 5.5 Medium · fixed in 5.15.0-1117.124~20.04.1 : update Linux kernel when convenient.
Data as of 28 Oct 2026, 11:57 UTC
- Patch
- Available – fixed in 5.15.0-1117.124~20.04.1, 5.15.0-1123.132~20.04.1, 5.15.0-1122.131~20.04.1 +58
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 25 Jul 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
- ubuntu.com/security/notices/USN-8726-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8727-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8728-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8760-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8726-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-8726-3 (opens in a new tab)
- ubuntu.com/security/notices/USN-8800-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8760-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-8728-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-8726-4 (opens in a new tab)
- ubuntu.com/security/notices/USN-8728-3 (opens in a new tab)
- ubuntu.com/security/notices/USN-8876-1 (opens in a new tab)
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 patch is available and has been released in multiple fixed Linux kernel versions including 5.15.0-1117.124~20.04.1 and related builds. Users and administrators should apply these official kernel updates to remediate the vulnerability. No additional mitigation actions are indicated by the vendor advisory.
Description
A vulnerability in the Linux kernel's io_uring/io-wq subsystem allows linked work items to continue running after exit has begun due to improper re-checking of the IO_WQ_BIT_EXIT flag. This flaw was fixed by moving the exit-bit check further inside the work run loop to cover all linked items. The issue affects certain Linux kernel versions prior to 5.15.0-1117.124~20.04.1 and related builds. The vulnerability has a medium severity with an impact on availability but does not affect confidentiality or integrity.
References
- ubuntu.com/security/CVE-2026-64425 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-64425 (opens in a new tab)
- git.kernel.org/linus/29bef9934b2521f787bb15dd1985d4c0d12ae02a (opens in a new tab)
- git.kernel.org/stable/c/14b7ecad2ec56699325180a744f4b19f046401bb (opens in a new tab)
- git.kernel.org/stable/c/1636d85dc139b07c0449308f2bb5e0c7a2e0da99 (opens in a new tab)
- git.kernel.org/stable/c/29bef9934b2521f787bb15dd1985d4c0d12ae02a (opens in a new tab)
- git.kernel.org/stable/c/6e2f51f3e06773c2ee98ad09738f0908b48f76f9 (opens in a new tab)
- git.kernel.org/stable/c/ab85765cbe3258b43dc6729af0e6ce3a87a133d8 (opens in a new tab)
- git.kernel.org/stable/c/b6f179a653a934736c88d820fe0098c3c2532549 (opens in a new tab)
- git.kernel.org/stable/c/d179533c610e1b4c6aa436e3c1fd1b719d2c727c (opens in a new tab)
- git.kernel.org/stable/c/ea61b04e1d7242cb37f5ed2cc91cf21a493f6597 (opens in a new tab)
- ubuntu.com/security/notices/USN-8726-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8727-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8728-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8760-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8726-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-8726-3 (opens in a new tab)
- ubuntu.com/security/notices/USN-8800-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8760-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-8728-2 (opens in a new tab)