CVE-2025-39964

Description

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.

Scoring

• CVSS: 7.8 (HIGH, 3.1)
• EPSS exploitation probability: Not yet available
• EPSS percentile: Not yet available

CISA KEV status

• Added to KEV: 2026-09-18
• Remediation due date: 2026-09-21
• Known ransomware campaign use: Unknown

Weakness types (CWE)

• CWE-362
• CWE-362

References

• 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
• https://cert-portal.siemens.com/productcert/html/ssa-019113.html
• https://cert-portal.siemens.com/productcert/html/ssa-457936.html
• https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2025-39964

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