CVE-2025-39964: Linux Kernel Race Condition Vulnerability

An official source reports active exploitation. Teams running Linux Kernel should verify exposure and begin risk-reduction work now.

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.

What changed

On September 18, 2026, this issue entered the urgent InfoSecNexus queue because exploitation is identified by an authoritative source. The source record, affected versions, and vendor remediation remain the controlling references; asset inventory and network context determine which systems should move first.

Why this matters

Linux Kernel may be embedded across servers, containers, appliances, and administration hosts. Package installation alone does not prove that the corrected code is running.

Exploit-first prioritization does not mean patching blindly. Confirm the vulnerable component is installed, identify the reachable attack path, preserve evidence of suspicious activity, and protect critical workloads while the permanent fix is deployed.

Immediate response plan

1. Map the advisory to distribution package versions and confirm the kernel or library currently loaded by each workload.
2. Apply the latest vendor remediation or isolate the vulnerable path when immediate patching is not possible.
3. Review available telemetry for exploitation attempts before restarting, rebuilding, or rotating evidence away.
4. Verify reboot or service-restart state, loaded modules, application health, and monitoring after remediation.