CVE-2025-39964 — Linux Kernel Race Condition Vulnerability

Impacted if

Linux Kernel

CISA Known Exploited Vulnerabilities

Added on 2026-09-18, federal remediation due 2026-09-21. Linux Kernel contains a race condition vulnerability which allows concurrent writes to the same AF_ALG socket causing data to be unpredictably interleaved and creating inconsistencies in the socket's internal state.

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.

First seen by AX-NEWS 13 Oct 2026, 00:00 UTC · latest story 13 Oct 2026, 00:00 UTC. Severity: NVD, or the CVE record while the NVD has not scored it. This product uses data from the NVD API but is not endorsed or certified by the NVD.