CVE-2026-99263: Linux kernel · io_uring/poll: avoid retry wakeup loss when dropping ownership
Source GCVE Database
Not known to be exploited · fixed in eb2a50d8235e4580fea9aa20f3fbe1a002c38cb1 : update Linux kernel when convenient.
Data as of 3 Nov 2026, 13:15 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 eb2a50d8235e4580fea9aa20f3fbe1a002c38cb1, d1f6850086ac6f8b0fa44fb19aa2a468c73ee071, afa407c02f3aa0fd872f86c9bf1b34502e0fa8f0 +5
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
|
| LinuxLinux | Affected
| Fixed in– |
Red Hatredhat/kernelpkg:rpm/redhat/kernelOther 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 has been implemented in the Linux kernel by changing the atomic operation to prevent missed wake-ups. Users should apply the official kernel update containing this fix once available. No other mitigation or workaround is indicated.
Description
A vulnerability in the Linux kernel's io_uring polling mechanism could cause a stall in processing requests due to a wakeup retry flag being lost when dropping ownership. This issue is addressed by changing the atomic operation used to ensure no wake-ups are missed.
References
- nvd.nist.gov/vuln/detail/CVE-2026-99263 (opens in a new tab)
- git.kernel.org/stable/c/41fae2e9e1fa3bee86aee0a25ba90e59ce5024bf (opens in a new tab)
- git.kernel.org/stable/c/4ef685b8505615729d75c875f52822238bf76ca6 (opens in a new tab)
- git.kernel.org/stable/c/521e8a65e9b45532295ba1082ef12be6e80c173b (opens in a new tab)
- git.kernel.org/stable/c/afa407c02f3aa0fd872f86c9bf1b34502e0fa8f0 (opens in a new tab)
- git.kernel.org/stable/c/d1f6850086ac6f8b0fa44fb19aa2a468c73ee071 (opens in a new tab)
- git.kernel.org/stable/c/eb2a50d8235e4580fea9aa20f3fbe1a002c38cb1 (opens in a new tab)