CVE-2025-40022 — crypto: af_alg - Fix incorrect boolean values in af_alg_ctx
In the Linux kernel, the following vulnerability has been resolved: crypto: af_alg - Fix incorrect boolean values in af_alg_ctx Commit 1b34cbbf4f01 ("crypto: af_alg - Disallow concurrent writes in af_alg_sendmsg") changed some fields from bool to 1-bit bitfields of type u32. However, some assignments to these fields, specifically 'more' and 'merge', assign values greater than 1. These relied on C's implicit conversion to bool, such that zero becomes false and nonzero becomes true. With a 1-bit bitfields of type u32 instead, mod 2 of the value is taken instead, resulting in 0 being assigned in some cases when 1 was intended. Fix this by restoring the bool type.
Who exploits it and how urgent it is
A 0–100 score combining confirmed exploitation, ransomware and APT use, public exploits, EPSS and severity.
How the score was calculated
- EPSS 0.2% (30-day exploitation probability)+2
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.
Remediation
Fixes and mitigations documented by the sources — linked to the original advisory.
No fix documented by the sources we poll. That does not mean none exists: check the vendor advisory.
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).
- No fix documented in the sources: reduce exposure and monitor the vendor advisory.
- 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 |
≥ 0f28c4adbc4a97437874c9b669fd7958a8c6d6ce and < 3a21698ace915a445bce2d0dcfc84b6d2199baf7≥ e4c1ec11132ec466f7362a95f36a506ce4dc08c9 and < d382d6daf0184490f366562469a5673f65ee2662≥ 1f323a48e9b5ebfe6dc7d130fdf5c3c0e92a07c8 and < 54506c6335690f4ef1b9f154e34f5a604c72c1ed≥ 7c4491b5644e3a3708f3dbd7591be0a570135b84 and < 8703940bd30b5ad94408d28d7192db2491cd3592≥ 9aee87da5572b3a14075f501752e209801160d3d and < 316b090c2fee964c307a634fecc7df269664b158≥ 45bcf60fe49b37daab1acee57b27211ad1574042 and < fbe96bd25423e61273d8831e995260b429d850b6≥ 1b34cbbf4f011a121ef7b2d7d6e6920a036d5285 and < d0ca0df179c4b21e2a6c4a4fb637aa8fa14575cb≥ 6.1.154 and < 6.1.155 and 3 more≥ 6.6.108 and < 6.6.109≥ 6.12.49 and < 6.12.50≥ 6.16.9 and < 6.16.10 |
Vulnerable | CVE Program (cve.org) e CISA ADP |
EPSS over time FIRST
Oct 13, 2026 → Oct 14, 2026 · 2 reading(s) · max 0.23%
Detection
Read off the CVSS vector and the weakness class. Starting points, not tested rules.
- Not enough vector or weakness data: use the affected application’s logs as a starting point.
Timeline
What happened to this CVE, newest first.
- 2026
- Record published
- Affected products added · linux/linux
- Source status changed · → Deferred
- Record created in this database
- 2025
- CVE published
Source activity
Repeated readings are counted rather than listed.
- 1× References added · Oct 15, 2026 – Oct 15, 2026
- 1× Official description updated · Oct 13, 2026 – Oct 13, 2026
References
10 on the record
- git.kernel.org/stable/c/8703940bd30b5ad94408d28d7192db2491cd3592
- git.kernel.org/stable/c/d0ca0df179c4b21e2a6c4a4fb637aa8fa14575cb
- cert-portal.siemens.com/productcert/html/ssa-082556.html
- git.kernel.org/stable/c/54506c6335690f4ef1b9f154e34f5a604c72c1ed
- git.kernel.org/stable/c/fbe96bd25423e61273d8831e995260b429d850b6
- cert-portal.siemens.com/productcert/html/ssa-457936.html
- git.kernel.org/stable/c/3a21698ace915a445bce2d0dcfc84b6d2199baf7
- cert-portal.siemens.com/productcert/html/ssa-019113.html
- git.kernel.org/stable/c/d382d6daf0184490f366562469a5673f65ee2662
- git.kernel.org/stable/c/316b090c2fee964c307a634fecc7df269664b158
Elsewhere on this site
Related CVEs (same products)
- Critical CVE-2026-99999 ipv4: validate checksum_start before completing checksum 13h
- Unknown CVE-2026-98432 ipv4: free inet_opt and ireq_opt after an RCU grace period 13h
- 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
- Unknown CVE-2026-98427 net/sched: codel: bound the dropping loop per dequeue call 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 CVSS score published by NVD, the CNA, CISA or GitHub so far.
- No fixed version, patch or mitigation documented.
- 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-2025-40022 is "crypto: af_alg - Fix incorrect boolean values in af_alg_ctx", rated Unknown. It affects Linux (Linux); versions are in the scope table. It is not in CISA KEV, which does not rule out exploitation. EPSS 0.23% 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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