CVE-2025-39964
crypto: af_alg - Disallow concurrent writes in af_alg_sendmsg
KEVMEDIUM 5.5EPSS 1.4%
In the Linux kernel, the following vulnerability has been resolved: crypto: af_alg - Disallow concurrent writes in af_alg_sendmsg Issuing two writes to the same af_alg socket is bogus as the data will be interleaved in an unpredictable fashion. Furthermore, concurrent writes may create inconsistencies in the internal socket state. Disallow this by adding a new ctx->write field that indiciates exclusive ownership for writing.
- Affected
- Linux
- CVSS v3.1 NVD
- 5.5 MEDIUM
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H - CVSS v3.1 CNA
- 7.8 HIGH
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H - EPSS
- 1.36% chance of exploitation in the next 30 days, 71st percentile
- CISA KEV
- added 2026-09-18
- Published
- 2025-10-13
- Updated
- 2026-10-15
Proof-of-concept exploits (3)
- OBLIVION-EDGE-VR-LLC/Archimedes0★ · 2026-01-11
- n1k0oowang/CVE-2025-39964_EXP3★ · 2025-11-13
- suominen/CVE-2025-399640★ · 2026-09-27
Exploit collections (1)
- linux/kernelctf/CVE-2025-39964_lts_cos_mitigationgoogle/security-research
Security advisories
- https://cert-portal.siemens.com/productcert/html/ssa-019113.html
- https://cert-portal.siemens.com/productcert/html/ssa-457936.html
- https://git.kernel.org/stable/c/0f28c4adbc4a97437874c9b669fd7958a8c6d6ce
- https://git.kernel.org/stable/c/1b34cbbf4f011a121ef7b2d7d6e6920a036d5285
- https://git.kernel.org/stable/c/1f323a48e9b5ebfe6dc7d130fdf5c3c0e92a07c8
- https://git.kernel.org/stable/c/45bcf60fe49b37daab1acee57b27211ad1574042
- https://git.kernel.org/stable/c/7c4491b5644e3a3708f3dbd7591be0a570135b84
- https://git.kernel.org/stable/c/9aee87da5572b3a14075f501752e209801160d3d
- https://git.kernel.org/stable/c/e4c1ec11132ec466f7362a95f36a506ce4dc08c9