CVE-2025-39964
Linux Kernel Race Condition Vulnerability
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.
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. Deadline for federal agencies: 2026-09-21.
2 articles across 2 outlets · first covered Sep 18, 2026 · latest Sep 18, 2026
Coverage timeline
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CISA Flags Two Linux Kernel Flaws Under Active Exploitationwww.cisa.gov · Sep 18, 2026
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CISA Flags Actively Exploited Linux Kernel Race Conditioncisa.gov · Sep 18, 2026