CVE-2026-99252: Linux kernel · io_uring/mpscq: disable preemption while pushing
Affects Linux kernelSource CVE Database V5
Not known to be exploited : upgrade to 8c94677e2b6145393d4c129fe0f5364b0e5000a5 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 8c94677e2b6145393d4c129fe0f5364b0e5000a5
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 Linux kernel to 8c94677e2b6145393d4c129fe0f5364b0e5000a5.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| LinuxLinux | Affected
| Fixed in
|
| LinuxLinux | Affected
| Fixed in– |
AI-suggested
A fix is available and has been committed in the Linux kernel at commit 8c94677e2b6145393d4c129fe0f5364b0e5000a5. Users should update to a kernel version including this fix to resolve the issue. No additional mitigation steps are indicated.
Description
A vulnerability in the Linux kernel's io_uring multi-producer single-consumer queue (mpscq) was addressed by disabling preemption during the push operation. The issue involved a timing window where a producer could be preempted after updating the queue tail but before linking the new node, causing consumers to spin-wait inefficiently, especially when consumer and producer tasks had differing priorities on the same CPU. The fix involves adding preempt_disable()/preempt_enable() calls around the push to prevent this race condition.