CVE-2025-40022

AF_ALG disruption via truncated boolean state

Published Oct 24, 2025 · Updated Oct 24, 2025

State-management error in Linux kernel 6.1.154, 6.6.108, 6.12.49, and 6.16.9 allows local users to disrupt AF_ALG operations. The af_alg_ctx more and merge fields truncate nonzero values to one bit, converting some intended true assignments into false state. Low-privileged local access is required, and the resulting state corruption affects the integrity and availability of kernel cryptographic socket processing.

CVSS severity5.8
Medium
EPSS probability0.22%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

State-management error in Linux kernel 6.1.154, 6.6.108, 6.12.49, and 6.16.9 allows local users to disrupt AF_ALG operations. The af_alg_ctx more and merge fields truncate nonzero values to one bit, converting some intended true assignments into false state. Low-privileged local access is required, and the resulting state corruption affects the integrity and availability of kernel cryptographic socket processing.

The record

CVE
CVE-2025-40022
Published
Oct 24, 2025
Updated
Oct 24, 2025
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
T1499
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Oct 24, 2025CVE publishedPublication date reported by the CVE source.
  2. Oct 24, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=0f28c4adbc4a97437874c9b669fd7958a8c6d6ce <3a21698ace915a445bce2d0dcfc84b6d2199baf7
  2. Affected versionversion=1b34cbbf4f011a121ef7b2d7d6e6920a036d5285 <d0ca0df179c4b21e2a6c4a4fb637aa8fa14575cb
  3. Affected versionversion=1f323a48e9b5ebfe6dc7d130fdf5c3c0e92a07c8 <54506c6335690f4ef1b9f154e34f5a604c72c1ed
  4. Affected versionversion=45bcf60fe49b37daab1acee57b27211ad1574042 <fbe96bd25423e61273d8831e995260b429d850b6
  5. Affected versionversion=6.1.154 <6.1.155
  6. Affected versionversion=6.12.49 <6.12.50
  7. Affected versionversion=6.16.9 <6.16.10
  8. Affected versionversion=6.6.108 <6.6.109
  9. Affected versionversion=7c4491b5644e3a3708f3dbd7591be0a570135b84 <8703940bd30b5ad94408d28d7192db2491cd3592
  10. Affected versionversion=9aee87da5572b3a14075f501752e209801160d3d <316b090c2fee964c307a634fecc7df269664b158
  11. Affected versionversion=e4c1ec11132ec466f7362a95f36a506ce4dc08c9 <d382d6daf0184490f366562469a5673f65ee2662

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=0f28c4adbc4a97437874c9b669fd7958a8c6d6ce <3a21698ace915a445bce2d0dcfc84b6d2199baf7; version=1b34cbbf4f011a121ef7b2d7d6e6920a036d5285 <d0ca0df179c4b21e2a6c4a4fb637aa8fa14575cb; version=1f323a48e9b5ebfe6dc7d130fdf5c3c0e92a07c8 <54506c6335690f4ef1b9f154e34f5a604c72c1ed; version=45bcf60fe49b37daab1acee57b27211ad1574042 <fbe96bd25423e61273d8831e995260b429d850b6; version=6.1.154 <6.1.155; version=6.12.49 <6.12.50; version=6.16.9 <6.16.10; version=6.6.108 <6.6.109; version=7c4491b5644e3a3708f3dbd7591be0a570135b84 <8703940bd30b5ad94408d28d7192db2491cd3592; version=9aee87da5572b3a14075f501752e209801160d3d <316b090c2fee964c307a634fecc7df269664b158; version=e4c1ec11132ec466f7362a95f36a506ce4dc08c9 <d382d6daf0184490f366562469a5673f65ee2662

Published CVSS scores

5.3SUSECVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:L/A:H
5.8SUSECVSS:4.0/AV:L/AC:H/AT:N/PR:L/UI:N/VC:N/VI:L/VA:H/SC:N/SI:N/SA:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

T1499Endpoint Denial of Service

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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