CVE-2026-75145: Ffmpeg

Medium severity, CVSS 5.8. EPSS: 0.2% chance of exploitation in the next 30 days.

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

Published 2026-08-19. Last modified 2026-08-31.