Medium 5.5Published Jul 25, 2026

CVE-2026-64425io_uring/io-wq: re-check IO_WQ_BIT_EXIT for each linked work item

Updated under an hour ago (Oct 26, 2026, 11:00 PM ET)

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It affects Linux and 4 other products. Add what you run to find out whether that includes you.

No exploitation reported and no EPSS estimate yet.

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Exploited in the last 30 days

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.

CVSS: 5.5 MEDIUM (v3.1, NVD)CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Weakness (CWE): Not given
Known exploited: Not in CISA's KEV catalog
EPSS (exploitation in the next 30 days): Not loaded for this CVE
Assigned by: Linux
NVD analysis: Modified
Record last updated: Oct 14, 2026
First seen by InfoSec Signals: Oct 9, 2026

Affected products

Affected products

Linux Linux linux:linux (from the name)	065dd936195a3466b8ebe5f9287400987ee3c063 builds before 14b7ecad2ec56699325180a744f4b19f046401bb; from 27e47500fac23d15b7dc93ff650bc4844d2581bd before d179533c610e1b4c6aa436e3c1fd1b719d2c727c; from d05d99573f81a091547b1778b9a50120f5d6c68a before 6e2f51f3e06773c2ee98ad09738f0908b48f76f9; from 85eb83694a91c89d9abe615d717c0053c3efa714 before ea61b04e1d7242cb37f5ed2cc91cf21a493f6597; from 2e8ca1078b14142db2ce51cbd18ff9971560046b before b6f179a653a934736c88d820fe0098c3c2532549; from bdf0bf73006ea8af9327cdb85cfdff4c23a5f966 before 1636d85dc139b07c0449308f2bb5e0c7a2e0da99; from 10dc959398175736e495f71c771f8641e1ca1907 before ab85765cbe3258b43dc6729af0e6ce3a87a133d8; from 10dc959398175736e495f71c771f8641e1ca1907 before 29bef9934b2521f787bb15dd1985d4c0d12ae02a; and 6 more ranges	CNA record
Siemens SIMATIC S7-1500 CPU 1518-4 PN/DP MFP siemens:simatic_s7_1500_cpu_1518_4_pn_dp_mfp (from the name)	from V3.1.6	CISA ADP
Siemens SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP siemens:simatic_s7_1500_cpu_1518f_4_pn_dp_mfp (from the name)	from V3.1.6	CISA ADP
Siemens SIPLUS S7-1500 CPU 1518-4 PN/DP MFP siemens:siplus_s7_1500_cpu_1518_4_pn_dp_mfp (from the name)	from V3.1.6	CISA ADP
linux linux_kernel linux:linux_kernel	from 5.10.253 before 5.10.261; from 5.15.203 before 5.15.212; from 6.1.167 before 6.1.178; from 6.6.122 before 6.6.145; from 6.12.68 before 6.12.96; from 6.18.8 before 6.18.39; from 6.19.1 before 7.1.4; 6.19; and 2 more ranges	NVD

References

References

https://git.kernel.org/stable/c/14b7ecad2ec56699325180a744f4b19f046401bb	patch
https://git.kernel.org/stable/c/d179533c610e1b4c6aa436e3c1fd1b719d2c727c	patch
https://git.kernel.org/stable/c/6e2f51f3e06773c2ee98ad09738f0908b48f76f9	patch
https://git.kernel.org/stable/c/ea61b04e1d7242cb37f5ed2cc91cf21a493f6597	patch
https://git.kernel.org/stable/c/b6f179a653a934736c88d820fe0098c3c2532549	patch
https://git.kernel.org/stable/c/1636d85dc139b07c0449308f2bb5e0c7a2e0da99	patch
https://git.kernel.org/stable/c/ab85765cbe3258b43dc6729af0e6ce3a87a133d8	patch
https://git.kernel.org/stable/c/29bef9934b2521f787bb15dd1985d4c0d12ae02a	patch
https://cert-portal.siemens.com/productcert/html/ssa-019113.html
https://cert-portal.siemens.com/productcert/html/ssa-457936.html

The CVE record on cve.org NVD's entry

The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.