CVE-2026-125098: medium-severity vulnerability in FFmpeg
FFmpeg through 9.0.2 WebP Decoder Information Disclosure via Short ALPH Chunk
Published
E-mail alert when it lands in KEV, gets a public PoC or its score goes up.
10Vexday Risk Score
No sign of exploitation. No public exploitation artifact known so far.
ssvc Trackcvss 4.8
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.
CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N
Affected products
FFmpeg · FFmpegRelated CVEs — FFmpeg
In the same product, most dangerous first.
CVE-2026-8461HIGHHeap out-of-bounds write via odd slice_height in FFmpeg MagicYUV decoderEPSS 1.6%CVE-2026-64831HIGHFFmpeg 8.0 - 8.1.2 Stack Buffer Overflow in Vulkan HEVC DecoderEPSS 0.9%CVE-2026-66040HIGHFFmpeg Heap Out-of-Bounds Write via PNG/APNG eXIf EncoderEPSS 0.8%CVE-2026-64834HIGHFFmpeg 0.6.3 - 8.1.2 Infinite Loop DoS via RTP/ASF DemuxerEPSS 0.7%CVE-2026-75143CRITICALFFmpeg Heap Buffer Overflow via RIST Protocol ReaderEPSS 0.7%CVE-2026-64830HIGHFFmpeg 2.1 - 8.1.2 Heap Buffer Overflow via VobSub Subtitle DemuxerEPSS 0.6%
References
https://code.ffmpeg.org/FFmpeg/FFmpeg/pulls/25715https://github.com/FFmpeg/FFmpeghttps://github.com/FFmpeg/FFmpeg/blob/n9.0.2/libavcodec/webp.c#L1257https://github.com/FFmpeg/FFmpeg/commit/92b318e0b33623720d9f128ad7bc5fa8277c34f7https://www.vulncheck.com/advisories/ffmpeg-through-9.0.2-webp-decoder-information-disclosure-via-short-alph-chunk