Answer in brief
CVE-2025-39964 records a Low severity (CVSS 3.3) vulnerability in crypto: af_alg - Disallow concurrent writes in af_alg_sendmsg. The current sources do not mark it as known exploited. The current feed maps Linux/Linux (generic), Linux/Linux (generic), Siemens/SIMATIC S7-1500 CPU 1518-4 PN/DP MFP (generic), Siemens/SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP (generic) and additional mapped packages. Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
Answer in brief
CVE-2025-39964 records a Low severity (CVSS 3.3) vulnerability in crypto: af_alg - Disallow concurrent writes in af_alg_sendmsg. The current sources do not mark it as known exploited. The current feed maps Linux/Linux (generic), Linux/Linux (generic), Siemens/SIMATIC S7-1500 CPU 1518-4 PN/DP MFP (generic), Siemens/SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP (generic) and additional mapped packages. Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
CVSS is 3.3. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.
Analysis status
Analysis pending evidence review
Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.
The current feed maps Linux/Linux (generic), Linux/Linux (generic), Siemens/SIMATIC S7-1500 CPU 1518-4 PN/DP MFP (generic), Siemens/SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP (generic) and additional mapped packages. Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| Linux/Linuxgeneric | >=8ff590903d5fc7f5a0a988c38267a3d08e6393a2 <0f28c4adbc4a97437874c9b669fd7958a8c6d6ce || >=8ff590903d5fc7f5a0a988c38267a3d08e6393a2 <e4c1ec11132ec466f7362a95f36a506ce4dc08c9 || >=8ff590903d5fc7f5a0a988c38267a3d08e6393a2 <1f323a48e9b5ebfe6dc7d130fdf5c3c0e92a07c8 || >=8ff590903d5fc7f5a0a988c38267a3d08e6393a2 <7c4491b5644e3a3708f3dbd7591be0a570135b84 || >=8ff590903d5fc7f5a0a988c38267a3d08e6393a2 <9aee87da5572b3a14075f501752e209801160d3d || >=8ff590903d5fc7f5a0a988c38267a3d08e6393a2 <45bcf60fe49b37daab1acee57b27211ad1574042 || >=8ff590903d5fc7f5a0a988c38267a3d08e6393a2 <1b34cbbf4f011a121ef7b2d7d6e6920a036d5285 | 0f28c4adbc4a97437874c9b669fd7958a8c6d6ce, e4c1ec11132ec466f7362a95f36a506ce4dc08c9, 1f323a48e9b5ebfe6dc7d130fdf5c3c0e92a07c8, 7c4491b5644e3a3708f3dbd7591be0a570135b84, 9aee87da5572b3a14075f501752e209801160d3d, 45bcf60fe49b37daab1acee57b27211ad1574042, 1b34cbbf4f011a121ef7b2d7d6e6920a036d5285 |
| Linux/Linuxgeneric | 2.6.38 | Not reported |
| Siemens/SIMATIC S7-1500 CPU 1518-4 PN/DP MFPgeneric | >=V3.1.6 <* | * |
| Siemens/SIMATIC S7-1500 CPU 1518F-4 PN/DP MFPgeneric | >=V3.1.6 <* | * |
| Siemens/SIPLUS S7-1500 CPU 1518-4 PN/DP MFPgeneric | >=V3.1.6 <* | * |
Published upstream
Oct 13, 2025
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Aug 5, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Jul 14, 2026
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.
Quoted source text, attributed separately from HOL analysis.
CVSS is 3.3. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.
Analysis status
Analysis pending evidence review
Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.
The current feed maps Linux/Linux (generic), Linux/Linux (generic), Siemens/SIMATIC S7-1500 CPU 1518-4 PN/DP MFP (generic), Siemens/SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP (generic) and additional mapped packages. Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| Linux/Linuxgeneric | >=8ff590903d5fc7f5a0a988c38267a3d08e6393a2 <0f28c4adbc4a97437874c9b669fd7958a8c6d6ce || >=8ff590903d5fc7f5a0a988c38267a3d08e6393a2 <e4c1ec11132ec466f7362a95f36a506ce4dc08c9 || >=8ff590903d5fc7f5a0a988c38267a3d08e6393a2 <1f323a48e9b5ebfe6dc7d130fdf5c3c0e92a07c8 || >=8ff590903d5fc7f5a0a988c38267a3d08e6393a2 <7c4491b5644e3a3708f3dbd7591be0a570135b84 || >=8ff590903d5fc7f5a0a988c38267a3d08e6393a2 <9aee87da5572b3a14075f501752e209801160d3d || >=8ff590903d5fc7f5a0a988c38267a3d08e6393a2 <45bcf60fe49b37daab1acee57b27211ad1574042 || >=8ff590903d5fc7f5a0a988c38267a3d08e6393a2 <1b34cbbf4f011a121ef7b2d7d6e6920a036d5285 | 0f28c4adbc4a97437874c9b669fd7958a8c6d6ce, e4c1ec11132ec466f7362a95f36a506ce4dc08c9, 1f323a48e9b5ebfe6dc7d130fdf5c3c0e92a07c8, 7c4491b5644e3a3708f3dbd7591be0a570135b84, 9aee87da5572b3a14075f501752e209801160d3d, 45bcf60fe49b37daab1acee57b27211ad1574042, 1b34cbbf4f011a121ef7b2d7d6e6920a036d5285 |
| Linux/Linuxgeneric | 2.6.38 | Not reported |
| Siemens/SIMATIC S7-1500 CPU 1518-4 PN/DP MFPgeneric | >=V3.1.6 <* | * |
| Siemens/SIMATIC S7-1500 CPU 1518F-4 PN/DP MFPgeneric | >=V3.1.6 <* | * |
| Siemens/SIPLUS S7-1500 CPU 1518-4 PN/DP MFPgeneric | >=V3.1.6 <* | * |
Published upstream
Oct 13, 2025
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Aug 5, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Jul 14, 2026
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.
Quoted source text, attributed separately from HOL analysis.