FFmpeg through 9.0.2 TTA Encoder Reachable Assertion via tta_encode_frame()

Advisories

FFmpeg through 9.0.2 TTA Encoder Reachable Assertion via tta_encode_frame()

Severity: medium
Date: 11/9/2026
Affecting: FFmpeg <= 9.0.2
CVE: CVE-2026-125187
CWE: CWE-617 Reachable Assertion
CVSS: 6.8
CVSS V4 Vector: CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N
References: https://code.ffmpeg.org/FFmpeg/FFmpeg/pulls/25694
Patch Commit
https://github.com/FFmpeg/FFmpeg/blob/n9.0.2/libavcodec/ttaenc.c#L93
https://github.com/FFmpeg/FFmpeg
Credit: Joshua Rogers (AISLE Research), Michael Niedermayer
Description: FFmpeg through 9.0.2 contains a reachable assertion vulnerability in the TTA encoder's tta_encode_frame() in libavcodec/ttaenc.c, which never reserves output packet space for the 4-byte CRC. Attackers can supply audio whose sample values and length produce a small, poorly compressible final frame, triggering the av_assert0() in flush_put_bits() and aborting applications transcoding to TTA.

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