CVE-2026-125259

Description

FFmpeg through 9.0.2 contains an integer overflow vulnerability in ff_prores_kostya_encode_init() that miscalculates frame_size_upper_bound using 32-bit arithmetic for large frame dimensions. Attackers can supply a high-resolution video transcoded with the prores_ks encoder, causing encode_frame() to write slices past an undersized packet buffer and corrupt heap memory.

References

• https://code.ffmpeg.org/FFmpeg/FFmpeg/pulls/25573
• https://github.com/FFmpeg/FFmpeg
• https://github.com/FFmpeg/FFmpeg/blob/n9.0.2/libavcodec/proresenc_kostya_common.c#L286
• https://github.com/FFmpeg/FFmpeg/commit/439b452f9fe916a9f7d8788ab6afee8fac846b0b
• https://www.vulncheck.com/advisories/ffmpeg-through-9.0.2-heap-buffer-overflow-via-prores-prores-ks-encoder