CVE-2026-99229: Linux kernel · io_uring/wait: don't spin on a stuck overflow list
Affects Linux kernelSource GCVE Database
Not known to be exploited.
Data as of 5 Nov 2026, 00:01 UTC
Rated by Threat Radar · CVSS not yet scored by NVD
Thin evidence
One scorer or none- EPSS
- 0.1% chance of exploitation in 30 days – higher than 4% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Exploitation evidence
Disclosed: evidence found.
CVE published 2 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 4 Nov 2026.
What to do
Affected software
| Product | Affected | Fixed in |
|---|---|---|
Ubuntu 26.10linuxpkg:deb/ubuntu/linux?arch=source&distro=stonkingOther threats | Affected
| Fixed in– |
Ubuntu 26.10linux-awspkg:deb/ubuntu/linux-aws?arch=source&distro=stonkingOther threats | Affected
| Fixed in– |
Ubuntu 26.10linux-azurepkg:deb/ubuntu/linux-azure?arch=source&distro=stonkingOther threats | Affected
| Fixed in– |
Ubuntu 26.10linux-azure-fdepkg:deb/ubuntu/linux-azure-fde?arch=source&distro=stonkingOther threats | Affected
| Fixed in– |
Ubuntu 26.10linux-gcppkg:deb/ubuntu/linux-gcp?arch=source&distro=stonkingOther threats | Affected
| Fixed in– |
Ubuntu 26.10linux-oraclepkg:deb/ubuntu/linux-oracle?arch=source&distro=stonkingOther 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 for this vulnerability is available in the Linux kernel versions listed as affected. Users should upgrade to a patched kernel version to resolve the issue. Since the problem is resolved in these versions, no additional mitigation steps are required beyond applying the official kernel updates.
Description
CVE-2026-99229 is a Linux kernel vulnerability in the io_uring subsystem where a task can spin indefinitely on a stuck overflow list. This occurs because io_cqring_wait_schedule() returns early without properly handling signals or timeouts, causing the task to spin in the kernel and become unkillable. The issue arises when the completion queue (CQ) ring appears full due to manipulated head pointers or mixed CQE entries, preventing the flushing of the overflow list. Only the application can resolve the stuck state by making room in the CQ ring.
References
- ubuntu.com/security/CVE-2026-99229 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-99229 (opens in a new tab)
- git.kernel.org/stable/c/4a89352edd8b3e20d1e1fb33f0fc297dd137149f (opens in a new tab)
- git.kernel.org/stable/c/c347691e5dc5481b2d6943c123619e04847fb0dc (opens in a new tab)
- git.kernel.org/stable/c/bf1d2ed84b3162e3b0e0bb7018ac59147da6e975 (opens in a new tab)
- git.kernel.org/stable/c/a6cfc85c6bf9498aaf1978b503f9663635a1aa22 (opens in a new tab)