CVE-2026-125175

EUVD-2026-120264
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.
ProviderTypeBase ScoreAtk. VectorAtk. ComplexityPriv. RequiredVector
VulnCheckCNA
3.3 LOW
LOCAL
LOW
NONE
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:N
Base Score
CVSS 3.x
EPSS Score
Percentile: Unknown
Early Detection
Affected products identified ahead of NVD analysis through intelligence sources (CNA/ADP records, vendor advisories, Enginsight analysis).
VendorProductVersionSource
ffmpegffmpeg
𝑥
≤ 9.0.2
CNA
Common Weakness Enumeration
References
https://code.ffmpeg.org/FFmpeg/FFmpeg/pulls/24464
https://github.com/FFmpeg/FFmpeg
https://github.com/FFmpeg/FFmpeg/blob/n9.0.2/libavcodec/flashsv.c#L248
https://github.com/FFmpeg/FFmpeg/commit/50d206a75b5e60261d71b25657ae04891eb60290
https://github.com/FFmpeg/FFmpeg/commit/cfb40c912927fdd2c1186b7b6aca468422da23db
https://www.vulncheck.com/advisories/ffmpeg-through-9.0.2-information-disclosure-via-flash-screen-video-decoder