KEV / Record
CVE-2025-39964: Linux Kernel Race Condition Vulnerability
Answer CVE-2025-39964 is in CISA's Known Exploited Vulnerabilities catalog. It was added on 2026-09-18, and US federal civilian agencies must act on it by 2026-09-21.
DCISA description
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.
ARequired 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.
RNotes and references
This vulnerability affects an open-source component, third-party library, protocol, or proprietary implementation that could be used by different products. For more information, please see: ; https://git.kernel.org/stable/c/0f28c4adbc4a97437874c9b669fd7958a8c6d6ce; https://git.kernel.org/stable/c/e4c1ec11132ec466f7362a95f36a506ce4dc08c9; https://git.kernel.org/stable/c/1f323a48e9b5ebfe6dc7d130fdf5c3c0e92a07c8; https://git.kernel.org/stable/c/7c4491b5644e3a3708f3dbd7591be0a570135b84; https://git.kernel.org/stable/c/9aee87da5572b3a14075f501752e209801160d3d; https://git.kernel.org/stable/c/45bcf60fe49b37daab1acee57b27211ad1574042; https://git.kernel.org/stable/c/1b34cbbf4f011a121ef7b2d7d6e6920a036d5285 ; BOD 26-04: https://www.cisa.gov/news-events/directives/bod-26-04-prioritizing-security-updates-based-risk ; Forensics Triage Requirements: https://www.cisa.gov/news-events/directives/bod-26-04-implementation-guidance-prioritizing-security-updates-based-risk ; https://nvd.nist.gov/vuln/detail/CVE-2025-39964
FRecord
VOther Linux entries in KEV
| CVE | Product | Added | Ransomware |
|---|---|---|---|
| CVE-2026-53266 | Kernel | New | Unknown |
| CVE-2025-39682 | Kernel | New | Unknown |
| CVE-2026-53362 | Kernel | Unknown | |
| CVE-2022-0995 | Kernel | Unknown | |
| CVE-2022-0492 | Kernel | Unknown | |
| CVE-2026-31431 | Kernel | Unknown | |
| CVE-2018-14634 | Kernel | Unknown | |
| CVE-2021-22555 | Kernel | Unknown | |
| CVE-2025-38352 | Kernel | Unknown | |
| CVE-2023-0386 | Kernel | Unknown |
This record repeats CISA's entry and is excluded from search indexes until an analyst note is added.
Source: CISA KEV catalog v2026.09.23, released 2026-09-23. Windows end 2026-09-23.