CVE-2025-39964
Linux Kernel Race Condition Vulnerability
IN CISA KEV
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.
- Vendor
- Linux
- Product
- Kernel
- CVSS 3.1
- 5.5 (medium), scored by NVD (primary)CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
- CVSS 3.1
- 7.8 (high), scored by 416baaa9-dc9f-4396-8d5f-8c081fb06d67CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
- CWE
- CWE-362
- Published
- 2025-10-13
- NVD modified
- 2026-10-15
- NVD status
- Analyzed
CISA KEV
- Date added
- 2026-09-18
- Due date
- 2026-09-21
- Ransomware use
- Unknown
- Required action
- Apply mitigations in accordance with vendor instructions, ensuring compliance with CISA’s BOD 26-04 Prioritizing Security Updates Based on Risk (see URL in Notes) guidance and CISA’s “Forensics Triage Requirements” (see URL in Notes). Follow applicable BOD 26-04 guidance for cloud services or discontinue use of the product if mitigations are unavailable. Stakeholders are responsible for evaluating each asset's internet exposure and ensuring adherence to BOD 26-04 patching guidelines.
EPSS
1.36% chance of exploitation in the next 30 days (percentile 71st)
FIRST EPSS, updated 17 Oct 2026. About EPSS
CVSS is severity, EPSS is likelihood, KEV means already exploited. EPSS is a statistical probability, not a certainty: a low score does not make a bug safe, and a high one does not prove it is being exploited.
References
- git.kernel.org (Patch)
- git.kernel.org (Patch)
- git.kernel.org (Patch)
- git.kernel.org (Patch)
- git.kernel.org (Patch)
- git.kernel.org (Patch)
- git.kernel.org (Patch)
- cert-portal.siemens.com (Third Party Advisory)
- cert-portal.siemens.com (Third Party Advisory)
- www.cisa.gov (US Government Resource)
Data last updated 18 Oct 2026. Sources: NVD API 2.0, CISA KEV catalog, FIRST EPSS. Links: NVD, CISA KEV. Metadata only. ThreatWire does not host exploit code.