CVE-2026-125175

Description

FFmpeg through 9.0.2 contains an information disclosure vulnerability in flashsv_decode_block() in libavcodec/flashsv.c that copies uninitialized heap memory into decoded frames when inflate output is short. Attackers can supply a crafted FLV with an FSV1 stream whose zlib block data decompresses short, then recover heap contents from the decoded or re-encoded output.

Affected products

Version statuses are supplied by the assigning organization. Consult the original record for detailed ranges and platform conditions.

References

• https://code.ffmpeg.org/FFmpeg/FFmpeg/pulls/24464 ↗
• https://github.com/FFmpeg/FFmpeg/commit/50d206a75b5e60261d71b25657ae04891eb60290 ↗
• https://github.com/FFmpeg/FFmpeg/commit/cfb40c912927fdd2c1186b7b6aca468422da23db ↗
• https://github.com/FFmpeg/FFmpeg/blob/n9.0.2/libavcodec/flashsv.c#L248 ↗
• https://github.com/FFmpeg/FFmpeg ↗
• https://www.vulncheck.com/advisories/ffmpeg-through-9.0.2-information-disclosure-via-flash-screen-video-decoder ↗