CVE-2025-39964
Linux · published 2025-10-13
Source record Collected from the National Vulnerability Database (NVD)
CISA Known Exploited Vulnerabilities
CISA lists this CVE as known exploited (added 2026-09-18).
- CISA's name for it: Linux Kernel Race Condition Vulnerability
- CISA's 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.
- Known ransomware campaign use, per CISA: Unknown
Source: CISA KEV catalog (CC0 1.0).
Description
Description by kernel.org via the CVE Program.
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.
Filed by kernel.org; not a statement by Linux.
Status at the source
- NVD status: Analyzed
Affected products, as the source lists them
| Vendor | Product | Versions |
|---|---|---|
| Linux | Linux | 8ff590903d5fc7f5a0a988c38267a3d08e6393a2 – before 0f28c4adbc4a97437874c9b669fd7958a8c6d6ce: affected 8ff590903d5fc7f5a0a988c38267a3d08e6393a2 – before e4c1ec11132ec466f7362a95f36a506ce4dc08c9: affected 8ff590903d5fc7f5a0a988c38267a3d08e6393a2 – before 1f323a48e9b5ebfe6dc7d130fdf5c3c0e92a07c8: affected 8ff590903d5fc7f5a0a988c38267a3d08e6393a2 – before 7c4491b5644e3a3708f3dbd7591be0a570135b84: affected 8ff590903d5fc7f5a0a988c38267a3d08e6393a2 – before 9aee87da5572b3a14075f501752e209801160d3d: affected 8ff590903d5fc7f5a0a988c38267a3d08e6393a2 – before 45bcf60fe49b37daab1acee57b27211ad1574042: affected 8ff590903d5fc7f5a0a988c38267a3d08e6393a2 – before 1b34cbbf4f011a121ef7b2d7d6e6920a036d5285: affected |
| Linux | Linux | 2.6.38: affected 0 – before 2.6.38: unaffected 5.10.245 – 5.10.* and earlier: unaffected 5.15.194 – 5.15.* and earlier: unaffected 6.1.154 – 6.1.* and earlier: unaffected 6.6.108 – 6.6.* and earlier: unaffected 6.12.49 – 6.12.* and earlier: unaffected 6.16.9 – 6.16.* and earlier: unaffected 6.17 – * and earlier: unaffected |
Added by siemens-SADP (Authorized Data Publisher)
| Vendor | Product | Versions |
|---|---|---|
| Siemens | SIMATIC S7-1500 CPU 1518-4 PN/DP MFP | V3.1.6 – before *: affected |
| Siemens | SIMATIC S7-1500 CPU 1518-4 PN/DP MFP | V3.1.6 – before *: affected |
| Siemens | SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP | V3.1.6 – before *: affected |
| Siemens | SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP | V3.1.6 – before *: affected |
| Siemens | SIPLUS S7-1500 CPU 1518-4 PN/DP MFP | V3.1.6 – before *: affected |
Products named in NVD's CPE match criteria (3)
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*cpe:2.3:o:siemens:simatic_s7-1500_cpu_1518-4_pn\/dp_mfp_firmware:*:*:*:*:*:*:*:*cpe:2.3:o:siemens:simatic_s7-1500_cpu_1518f-4_pn\/dp_mfp_firmware:*:*:*:*:*:*:*:*
DeSpy has not checked any unit, hardware revision or firmware. A product missing here is not a statement that it is unaffected.
Scores, as their sources published them
- CVSS 3.1: 7.8 HIGH — as published by kernel.org (Secondary)
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H - CVSS 3.1: 5.5 MEDIUM — as published by NIST (Primary)
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H - SSVC — CISA's assessment (SSVC 2.0.3, CISA Coordinator): Exploitation: active · Automatable: no · Technical impact: total
DeSpy does not score records. These are the sources' own values.
Weaknesses
Sources
References the source lists
- https://git.kernel.org/stable/c/0f28c4adbc4a97437874c9b669fd7958a8c6d6ce
- https://git.kernel.org/stable/c/1b34cbbf4f011a121ef7b2d7d6e6920a036d5285
- https://git.kernel.org/stable/c/1f323a48e9b5ebfe6dc7d130fdf5c3c0e92a07c8
- https://git.kernel.org/stable/c/45bcf60fe49b37daab1acee57b27211ad1574042
- https://git.kernel.org/stable/c/7c4491b5644e3a3708f3dbd7591be0a570135b84
- https://git.kernel.org/stable/c/9aee87da5572b3a14075f501752e209801160d3d
- https://git.kernel.org/stable/c/e4c1ec11132ec466f7362a95f36a506ce4dc08c9
- https://cert-portal.siemens.com/productcert/html/ssa-019113.html
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2025-39964
Source dates: published 2025-10-13, last changed 2026-09-19. DeSpy's copy of this version is dated 2026-09-28.
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