CVE-2026-107676

FFmpeg through 9.0.2 contains an uninitialized memory disclosure vulnerability in av_dynamic_hdr_plus_to_t35() that leaves up to three payload bytes uninitialized when tone_mapping_flag is 0. Attackers can supply crafted Matroska T.35 BlockAdditional or HEVC/AV1 SEI metadata so that remuxing or transcoding writes leaked process memory into output files.

CVSS 4.0

4.8CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N

CVSS 3.1

3.3CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:N

EPSS

0.1% chance of exploitation in the next 30 days; higher than 3% of CVEs (scores of 2026-10-25)

CWE

CWE-908

Published

2026-10-08

Modified

2026-10-14

Record from

the NVD, synced 2026-10-19

Affected

• ffmpeg:ffmpeg

References

• https://code.ffmpeg.org/FFmpeg/FFmpeg/commit/2c2f6e96e31795ae95a8f8323a493ffbc493111f
• https://code.ffmpeg.org/FFmpeg/FFmpeg/pulls/24590
• https://ffmpeg.org/
• https://github.com/FFmpeg/FFmpeg/blob/n9.0.2/libavutil/hdr_dynamic_metadata.c#L374-L385
• https://www.vulncheck.com/advisories/ffmpeg-through-9.0.2-uninitialized-memory-disclosure-via-hdr10-metadata-serializer

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