CVE-2026-64425: Linux kernel · io_uring/io-wq: re-check IO_WQ_BIT_EXIT for each linked work item
Affects Linux kernelSource CVE Database V5
Not known to be exploited · fixed in ea61b04e1d7242cb37f5ed2cc91cf21a493f6597 : update Linux kernel when convenient.
Data as of 6 Nov 2026, 17:04 UTC
Rated by Threat Radar · No CVSS score from NVD or the CNA
Thin evidence
One scorer or none- CISA SSVC
- Exploitation
- No evidence of active exploitation and no public proof of concept
- Automatable
- Attackers cannot reliably automate steps 1–4 of the kill chain
- Technical impact
- Limited control over the software or limited information exposure
CISA SSVC assessment, 2026-11-06.
- Patch
- Available – fixed in ea61b04e1d7242cb37f5ed2cc91cf21a493f6597, d179533c610e1b4c6aa436e3c1fd1b719d2c727c, b6f179a653a934736c88d820fe0098c3c2532549 +11
Exploitation evidence
Disclosed: evidence found.
CVE published 25 Jul 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 6 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– |
Description
In the Linux kernel, the following vulnerability has been resolved: io_uring/io-wq: re-check IO_WQ_BIT_EXIT for each linked work item commit 10dc95939817 ("io_uring/io-wq: check IO_WQ_BIT_EXIT inside work run loop") fixed the obvious case where io_worker_handle_work() took one exit-bit snapshot before draining pending work, but the fix stops one level too early. io_worker_handle_work() now re-checks IO_WQ_BIT_EXIT in its outer work run loop, yet it still snapshots that bit once before processing a whole dependent linked-work chain. If io_wq_exit_start() sets IO_WQ_BIT_EXIT after the first linked item has started, the remaining linked items can still reuse stale do_kill = false, skip IO_WQ_WORK_CANCEL, and continue running after exit has begun. Move the check further inside, so it covers linked items too. Note: this is a syzbot special as it loves setting up tons of slow linked work on weird devices like msr that take forever to read, and immediately close the ring. Exit then takes a long time.
References
- git.kernel.org/stable/c/14b7ecad2ec56699325180a744f4b19f046401bb (opens in a new tab)
- git.kernel.org/stable/c/d179533c610e1b4c6aa436e3c1fd1b719d2c727c (opens in a new tab)
- git.kernel.org/stable/c/6e2f51f3e06773c2ee98ad09738f0908b48f76f9 (opens in a new tab)
- git.kernel.org/stable/c/ea61b04e1d7242cb37f5ed2cc91cf21a493f6597 (opens in a new tab)
- git.kernel.org/stable/c/b6f179a653a934736c88d820fe0098c3c2532549 (opens in a new tab)
- git.kernel.org/stable/c/1636d85dc139b07c0449308f2bb5e0c7a2e0da99 (opens in a new tab)
- git.kernel.org/stable/c/ab85765cbe3258b43dc6729af0e6ce3a87a133d8 (opens in a new tab)
- git.kernel.org/stable/c/29bef9934b2521f787bb15dd1985d4c0d12ae02a (opens in a new tab)
- cert-portal.siemens.com/productcert/html/ssa-019113.html (opens in a new tab)
- cert-portal.siemens.com/productcert/html/ssa-457936.html (opens in a new tab)