CVE-2026-125233: high-severity vulnerability in FFmpeg
FFmpeg through 9.0.2 Heap Buffer Overflow via DVB Subtitle Encoder
Published
E-mail alert when it lands in KEV, gets a public PoC or its score goes up.
18Vexday Risk Score
No sign of exploitation. No public exploitation artifact known so far.
ssvc Trackcvss 8.5
FFmpeg through 9.0.2 contains a heap buffer overflow vulnerability in dvbsub_encode() in libavcodec/dvbsubenc.c that undercounts each CLUT segment header by two bytes. Attackers can supply a file with many bitmap subtitle rectangles that, when transcoded to the dvbsub encoder, writes past the output buffer and corrupts heap memory.
CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/VC:H/VI:H/VA:H/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/24913https://github.com/FFmpeg/FFmpeghttps://github.com/FFmpeg/FFmpeg/blob/n9.0.2/libavcodec/dvbsubenc.c#L363https://github.com/FFmpeg/FFmpeg/commit/7f80b2ad83f37a4998d9617495c92b28a7339a90https://www.vulncheck.com/advisories/ffmpeg-through-9.0.2-heap-buffer-overflow-via-dvb-subtitle-encoder