CVE-2026-99255: Linux kernel · io_uring/io-wq: don't hide a link from cancellations
Affects Linux kernelSource CVE Database V5
Not known to be exploited · fixed in ebe8e97fb99d9f374c482902a00677cfd24a6c27 : update Linux kernel when convenient.
Data as of 3 Nov 2026, 11:46 UTC
Rated Medium by Threat Radar's AI analysis · CVSS not yet scored by NVD
Thin evidence
One scorer or none- Patch
- Available – fixed in ebe8e97fb99d9f374c482902a00677cfd24a6c27, d39ebc7a583d650b1d6da9b45e2ce96ad4d877e4, 98470f164286f7f62aaee519d4d11b9370ce6d7b +2
Exploitation evidence
Disclosed: evidence found.
CVE published 3 Nov 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: 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 3 Nov 2026.
What to do
Upgrade to a fixed release listed under Affected software.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | 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 in the Linux kernel in commits ebe8e97fb99d9f374c482902a00677cfd24a6c27, d39ebc7a583d650b1d6da9b45e2ce96ad4d877e4, 98470f164286f7f62aaee519d4d11b9370ce6d7b, 92e20e9c72bdf6cfa6f84eded7b33399bc7061da, and 3e02b8df0e9fa1423ac2a4e03409a9329c30ac49. Users should upgrade to a fixed kernel version incorporating these commits to resolve the issue.
Description
CVE-2026-99255 is a vulnerability in the Linux kernel's io_uring subsystem related to request cancellation handling. A timing window exists where linked requests can be missed during task exit cancellations, causing tasks to sleep indefinitely and potentially hang. This issue affects Linux kernel version 5.5 and has been fixed in later commits.
References
- git.kernel.org/stable/c/98470f164286f7f62aaee519d4d11b9370ce6d7b (opens in a new tab)
- git.kernel.org/stable/c/d39ebc7a583d650b1d6da9b45e2ce96ad4d877e4 (opens in a new tab)
- git.kernel.org/stable/c/ebe8e97fb99d9f374c482902a00677cfd24a6c27 (opens in a new tab)
- git.kernel.org/stable/c/3e02b8df0e9fa1423ac2a4e03409a9329c30ac49 (opens in a new tab)
- git.kernel.org/stable/c/92e20e9c72bdf6cfa6f84eded7b33399bc7061da (opens in a new tab)