---
cve: "CVE-2025-39964"
severity: "HIGH"
cvss: 7.8
epss: "0.3%"
vendor: "Linux"
kev: true
exploited: true
published: "2025-10-13 14:15:34"
tags: [cve, security, high]
source: tsecurity.de CVE-Dossier
exported: "2026-09-20T01:33:42+02:00"
---

# CVE-2025-39964

> 7.8 HIGH · ⚠️ CISA KEV (1 Tage) · 🔓 Exploited

## Beschreibung

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.

## CVSS-Vektor

```
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
```

| Metrik | Wert | Bewertung |
|---|---|---|
| AV Angriffsvektor | Lokal | good |
| AC Komplexität | Gering | bad |
| PR Privilegien | Gering | warn |
| UI Interaktion | Keine | bad |
| S Scope | Unverändert | good |
| C Vertraulichkeit | Hoch | bad |
| I Integrität | Hoch | bad |
| A Verfügbarkeit | Hoch | bad |

## Patch verfügbar (OSV)

- Kernel ≥ 5.10.245
- Kernel ≥ 5.15.194
- Kernel ≥ 6.1.154
- Kernel ≥ 6.6.108
- Kernel ≥ 6.12.49
- Kernel ≥ 6.16.9

## Referenzen

- <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>
- <https://cert-portal.siemens.com/productcert/html/ssa-019113.html>
- <https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2025-39964>

---
_Exportiert aus dem [tsecurity.de CVE-Dossier](https://tsecurity.de/cve?cve=CVE-2025-39964) · Datenquellen: EUVD (ENISA), NVD, OSV, CISA KEV, FIRST EPSS, Exploit-DB, BSI BITS_