Linux Kernel Race Condition (CVE‑2025‑39964) Risks AF_ALG Socket Integrity
What It Is – A race‑condition flaw in the Linux kernel’s AF_ALG socket implementation permits concurrent writes that can interleave data and corrupt the socket’s internal state.
Exploitability – The vulnerability is publicly disclosed (CVE‑2025‑39964) and assigned a CVSS 3.1 base score of 7.8 (High). No public exploit has been observed yet, but the flaw is exploitable by an unprivileged local attacker who can open AF_ALG sockets.
Affected Products – All Linux distributions that ship the affected kernel version (5.15 and earlier). The issue is kernel‑wide, so any workload running on Linux—cloud VMs, containers, on‑prem servers, and embedded devices—is potentially exposed.
Why It Matters for Trust & Control Assurance
- Patch Management & Evidence – Demonstrating timely patching is a core control in most frameworks; this CVE underscores the need for continuous, auditable patch‑status monitoring.
- Configuration Baseline Integrity – AF_ALG sockets are often used for cryptographic off‑load; a corrupted state could undermine data‑integrity assurances that auditors scrutinize.
- Supply‑Chain Confidence – Linux underpins many SaaS and cloud services. A kernel‑level flaw erodes the trust signal that providers can maintain a hardened, verifiable runtime environment.
Recommended Actions
- Apply the upstream kernel patch released by the Linux maintainers (or upgrade to a kernel version where the fix is back‑ported).
- Validate kernel version inventory across all assets and capture the patch‑status as immutable evidence for audit trails.
- Enable continuous kernel‑version monitoring in your configuration‑management or CMDB tooling to flag drift in real time.
- Test critical workloads that rely on AF_ALG sockets after patching to ensure cryptographic functionality remains intact.
Source: CISA KEV – CVE‑2025‑39964