CVE-2026-125098

EUVD-2026-120252
FFmpeg through 9.0.2 contains an information disclosure vulnerability in vp8_lossy_decode_alpha() in libavcodec/webp.c that leaves alpha plane memory uninitialized for short uncompressed ALPH chunks. Attackers can supply a crafted WebP image whose ALPH chunk is shorter than width * height to disclose stale pixel data from previously decoded frames.
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/25715
https://github.com/FFmpeg/FFmpeg
https://github.com/FFmpeg/FFmpeg/blob/n9.0.2/libavcodec/webp.c#L1257
https://github.com/FFmpeg/FFmpeg/commit/92b318e0b33623720d9f128ad7bc5fa8277c34f7
https://www.vulncheck.com/advisories/ffmpeg-through-9.0.2-webp-decoder-information-disclosure-via-short-alph-chunk