---
cve: "CVE-2026-75145"
severity: "MEDIUM"
cvss: 5.8
epss: "12%"
vendor: "FFMPEG"
kev: false
exploited: false
published: "2026-08-19 17:21:12"
tags: [cve, security, medium]
source: tsecurity.de CVE-Dossier
exported: "2026-09-16T17:31:28+02:00"
---

# CVE-2026-75145

> 5.8 MEDIUM

## Beschreibung

FFmpeg before commit b4c199c contains an incorrect integer narrowing conversion in the AV1 RTP packetizer (libavformat/rtpenc_av1.c). The OBU size is cast to long before comparison against the remaining frame size. On targets where long is 32 bits, including 64-bit Windows, sufficiently large OBU size values are sign-flipped by the narrowing cast, producing a negative value that passes the payload size check. This allows an oversized OBU to bypass the safety bound on affected platforms, leading to out-of-bounds memory access when the oversized value is subsequently used as a copy length.

## CVSS-Vektor

```
CVSS:4.0/AV:L/AC:H/AT:N/PR:N/UI:P/VC:L/VI:L/VA:H/SC:N/SI:N/SA:N
```

| Metrik | Wert | Bewertung |
|---|---|---|
| AV Angriffsvektor | Lokal | good |
| AC Komplexität | Hoch | good |
| PR Privilegien | Keine | bad |

## Referenzen

- <https://code.ffmpeg.org/FFmpeg/FFmpeg/pulls/24090>
- <https://code.ffmpeg.org/FFmpeg/FFmpeg/commit/b4c199c5906ff53368926c2a5839881f41957e7f>
- <https://www.vulncheck.com/advisories/ffmpeg-integer-narrowing-conversion-oob-memory-access-in-av1-rtp-packetizer>

---
_Exportiert aus dem [tsecurity.de CVE-Dossier](https://tsecurity.de/cve?cve=CVE-2026-75145) · Datenquellen: EUVD (ENISA), NVD, OSV, CISA KEV, FIRST EPSS, Exploit-DB, BSI BITS_