# CVE-2026-75145

## Summary

- **CVE ID:** CVE-2026-75145
- **Severity:** MEDIUM
- **CVSS Score:** 5.8 (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)
- **CWE:** CWE-681
- **Published:** Aug 19, 2026
- **Last Modified:** Aug 21, 2026

## Description

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.

## Affected Products

- FFmpeg — FFmpeg (0)

## References

- [CNA](https://code.ffmpeg.org/FFmpeg/FFmpeg/pulls/24090)
- [CNA](https://code.ffmpeg.org/FFmpeg/FFmpeg/commit/b4c199c5906ff53368926c2a5839881f41957e7f)
- [CNA](https://www.vulncheck.com/advisories/ffmpeg-integer-narrowing-conversion-oob-memory-access-in-av1-rtp-packetizer)

## Exploitation Prediction (EPSS)

- **EPSS Score:** 0.12%
- **EPSS Percentile:** 1.9

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_Exported from OnDuty AI Vulnerability Intelligence on 2026-09-10._