Medium

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

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.

Published Jul 25, 2026 · Updated Oct 15, 2026 · Sources: CVE Program (cve.org) e CISA ADP, NIST National Vulnerability Database, GitHub Security Advisories · CNA: Linux

Low

Who exploits it and how urgent it is

A 0–100 score combining confirmed exploitation, ransomware and APT use, public exploits, EPSS and severity.

No exploitation signal in the sources consulted so far.

How the score was calculated

EPSS 0.1% (30-day exploitation probability)+0
Technical severity (medium)+3

The score orders the patch queue; it does not replace your asset context (internet exposure, criticality, compensating controls).

Triage

Is it exploited, how likely is exploitation, what does it touch, and how severe do the sources call it.

Exploitation

Not confirmed

Not in CISA KEV — an absence of record, not proof it is unexploited.

EPSS FIRST

0.13%

ahead of 2% of scored CVEs · Oct 14, 2026

Affects

Linux

Linux and 1 more

CVSS base

5.5

Medium · 2 source(s)

Remediation

Fixes and mitigations documented by the sources — linked to the original advisory.

Documented patch — git.kernel.org (NIST National Vulnerability Database)
Documented patch — git.kernel.org (NIST National Vulnerability Database)
Documented patch — git.kernel.org (NIST National Vulnerability Database)
Documented patch — git.kernel.org (NIST National Vulnerability Database)
Documented patch — git.kernel.org (NIST National Vulnerability Database)
Documented patch — git.kernel.org (NIST National Vulnerability Database)
Documented patch — git.kernel.org (NIST National Vulnerability Database)
Documented patch — git.kernel.org (NIST National Vulnerability Database)

First 24 hours

Ordered from the record’s own fields — exposure first, because you cannot patch what you have not found. A rule-generated starting point.

Identify exposed assets running the affected vendor/product/version combinations (Linux Linux, Linux Linux Kernel).
Apply the fixed version or the patch documented under Remediation.
Search available logs for exploit probes, errors and authentication anomalies.

Affected scope

Vendor, product and versions as the sources word them.

Vendor	Product	Versions	Status	Source
Linux	Linux	≥ d05d99573f81a091547b1778b9a50120f5d6c68a and < 6e2f51f3e06773c2ee98ad09738f0908b48f76f9version 6.19≥ 6.18.8 and < 6.18.39≥ 6.12.68 and < 6.12.96≥ 6.6.122 and < 6.6.145≥ 6.1.167 and < 6.1.178≥ 5.15.203 and < 5.15.212≥ 5.10.253 and < 5.10.261 and 7 more ≥ 10dc959398175736e495f71c771f8641e1ca1907 and < 29bef9934b2521f787bb15dd1985d4c0d12ae02a≥ 10dc959398175736e495f71c771f8641e1ca1907 and < ab85765cbe3258b43dc6729af0e6ce3a87a133d8≥ bdf0bf73006ea8af9327cdb85cfdff4c23a5f966 and < 1636d85dc139b07c0449308f2bb5e0c7a2e0da99≥ 2e8ca1078b14142db2ce51cbd18ff9971560046b and < b6f179a653a934736c88d820fe0098c3c2532549≥ 85eb83694a91c89d9abe615d717c0053c3efa714 and < ea61b04e1d7242cb37f5ed2cc91cf21a493f6597≥ 27e47500fac23d15b7dc93ff650bc4844d2581bd and < d179533c610e1b4c6aa436e3c1fd1b719d2c727c≥ 065dd936195a3466b8ebe5f9287400987ee3c063 and < 14b7ecad2ec56699325180a744f4b19f046401bb	Vulnerable	CVE Program (cve.org) e CISA ADP
Linux	Linux Kernel	≥ 5.10.253 and < 5.10.261version 6.19-rc8version 6.19-rc7version 6.19≥ 6.19.1 and < 7.1.4≥ 6.18.8 and < 6.18.39≥ 6.12.68 and < 6.12.96≥ 6.6.122 and < 6.6.145 and 2 more ≥ 6.1.167 and < 6.1.178≥ 5.15.203 and < 5.15.212	Vulnerable	NIST National Vulnerability Database

Attack characteristics

The CVSS vector, decoded. It describes the attack, not your exposure to it.

Attack vector

Local

Attack complexity

Low

Privileges required

Low

User interaction

None

Scope

Unchanged

Confidentiality

None

Integrity

None

Availability

High

Every base score collected

Sources score independently and may disagree; each row says who scored it and under which version.

Score	Version	Severity	Expl.	Impact	Scored by
5.5	CVSS 3.1	Medium	1.8	3.6	nvd@nist.gov via NIST National Vulnerability Database
5.5	CVSS 3.1	Medium	—	—	GitHub, Inc. via GitHub Security Advisories

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H (score shown at the top: nvd@nist.gov)

Detection

Read off the CVSS vector and the weakness class. Starting points, not tested rules.

Local/physical vector: focus on endpoint telemetry (EDR) from affected hosts.

endpoint telemetry (EDR)

Timeline

What happened to this CVE, newest first.

2026
Fix documented
Oct 15, 2026 · NIST National Vulnerability Database
Affected products added · linux/linux kernel
Oct 15, 2026 · NIST National Vulnerability Database
CVSS changed · 5.5
Oct 15, 2026 · NIST National Vulnerability Database
Source status changed · Published → Modified
Oct 15, 2026 · NIST National Vulnerability Database
Record published
Oct 15, 2026
Source status changed · → Published
Oct 15, 2026 · CVE Program (cve.org) e CISA ADP
Record created in this database
Oct 15, 2026 · CVE Program (cve.org) e CISA ADP
CVE published
Jul 25, 2026 · Linux

Source activity

Repeated readings are counted rather than listed.

2× References added · Oct 15, 2026 – Oct 15, 2026
1× Official description updated · Oct 15, 2026 – Oct 15, 2026

References

12 on the record

git.kernel.org/stable/c/ab85765cbe3258b43dc6729af0e6ce3a87a133d8
Patch, CVE Program (cve.org) e CISA ADP
git.kernel.org/stable/c/6e2f51f3e06773c2ee98ad09738f0908b48f76f9
Patch, CVE Program (cve.org) e CISA ADP
git.kernel.org/stable/c/b6f179a653a934736c88d820fe0098c3c2532549
Patch, CVE Program (cve.org) e CISA ADP
git.kernel.org/stable/c/ea61b04e1d7242cb37f5ed2cc91cf21a493f6597
Patch, CVE Program (cve.org) e CISA ADP
git.kernel.org/stable/c/1636d85dc139b07c0449308f2bb5e0c7a2e0da99
Patch, CVE Program (cve.org) e CISA ADP
git.kernel.org/stable/c/29bef9934b2521f787bb15dd1985d4c0d12ae02a
Patch, CVE Program (cve.org) e CISA ADP
git.kernel.org/stable/c/14b7ecad2ec56699325180a744f4b19f046401bb
Patch, CVE Program (cve.org) e CISA ADP
git.kernel.org/stable/c/d179533c610e1b4c6aa436e3c1fd1b719d2c727c
Patch, CVE Program (cve.org) e CISA ADP
cert-portal.siemens.com/productcert/html/ssa-457936.html
NIST National Vulnerability Database
cert-portal.siemens.com/productcert/html/ssa-019113.html
NIST National Vulnerability Database
github.com/advisories/GHSA-rmw8-w7cg-rwfm
GitHub Security Advisories
nvd.nist.gov/vuln/detail/CVE-2026-64425
GitHub Security Advisories

Elsewhere on this site

Linux
every CVE for this vendor

Related CVEs (same products)

Critical CVE-2026-99999 ipv4: validate checksum_start before completing checksum 7h
Unknown CVE-2026-98432 ipv4: free inet_opt and ireq_opt after an RCU grace period 7h
Unknown CVE-2026-98429 RDMA/efa: Keep EQ resources alive while IRQ is registered 1d
Unknown CVE-2026-98424 wifi: cfg80211: undo netns switch if renaming the wiphy fails 1d
Unknown CVE-2026-98425 wifi: mac80211: don't warn when an IBSS has no channel to scan 1d
Unknown CVE-2026-98426 wifi: mwifiex: fix IRQ leak using wrong index in MSI-X error path 1d

Not in any source we poll

Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.

No CISA SSVC assessment.
No CWE classification.
No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
No exploit packet captures, log samples, or incident case IDs supplied.

Answered from this record

Text assembled only from the fields above — no additional claims.

What should defenders know first?

CVE-2026-64425 is "io_uring/io-wq: re-check IO_WQ_BIT_EXIT for each linked work item", rated Medium. It affects Linux (Linux); versions are in the scope table. It is not in CISA KEV, which does not rule out exploitation. CVSS 5.5 describes technical severity. EPSS 0.13% estimates the probability of exploitation in 30 days; neither replaces your asset context. First verify whether exposed or business-critical assets run the affected versions, apply vendor fixes or mitigations, and preserve logs for review.

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