CVE-2026-98858: Linux kernel · io_uring: fix task_work add use-after-free with SQPOLL
Affects Linux kernelSource CVE Database V5
Not known to be exploited · fixed in a92193c91e8839fe5fc209616ea95465ae4b919d : patch Linux kernel soon.
Data as of 26 Oct 2026, 17:16 UTC
Rated High by Threat Radar's AI analysis · CVSS not yet scored by NVD
- 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.
- Patch
- Available – fixed in a92193c91e8839fe5fc209616ea95465ae4b919d, 891bd8335a0de3bb15c3b797ce3026bbb0dbef6c, 395b25968fe854d4efaa19a8e9b7a5b6d1b3eea3 +1
Exploitation evidence
Disclosed: evidence found.
CVE published 18 Oct 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 Linux kernel to a92193c91e8839fe5fc209616ea95465ae4b919d, 891bd8335a0de3bb15c3b797ce3026bbb0dbef6c, 395b25968fe854d4efaa19a8e9b7a5b6d1b3eea3 or 42b3332efacfd2140be4cd0dedad4fb96b8ae90e.
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– |
Linuxlinux/kernelpkg:deb/linux/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 is available and has been applied in the Linux kernel commits identified by hashes a92193c91e8839fe5fc209616ea95465ae4b919d, 891bd8335a0de3bb15c3b797ce3026bbb0dbef6c, 395b25968fe854d4efaa19a8e9b7a5b6d1b3eea3, and 42b3332efacfd2140be4cd0dedad4fb96b8ae90e. Users should update to a patched kernel version to remediate this vulnerability.
Description
A use-after-free vulnerability in the Linux kernel's io_uring subsystem with SQPOLL enabled has been fixed. The issue occurs when the sqpoll thread processes task_work independently, potentially freeing context structures while they are still accessed, leading to memory corruption detected by KASAN. The fix involves holding an RCU read lock during the addition of task work and waiting for a grace period before freeing context structures.
References
- git.kernel.org/stable/c/42b3332efacfd2140be4cd0dedad4fb96b8ae90e (opens in a new tab)
- git.kernel.org/stable/c/891bd8335a0de3bb15c3b797ce3026bbb0dbef6c (opens in a new tab)
- git.kernel.org/stable/c/395b25968fe854d4efaa19a8e9b7a5b6d1b3eea3 (opens in a new tab)
- git.kernel.org/stable/c/a92193c91e8839fe5fc209616ea95465ae4b919d (opens in a new tab)