CVE-2026-125103

Description

FFmpeg through 9.0.2 contains an information disclosure vulnerability in ff_mlz_decompression() in libavcodec/mlz.c, which accepts string codes beyond the dictionary's next free code. Attackers can supply a crafted MPEG-4 ALS file with malformed initial or out-of-range codes to copy uninitialized heap bytes into decoded audio output.

Affected products

Version statuses are supplied by the assigning organization. Consult the original record for detailed ranges and platform conditions.

References

• https://code.ffmpeg.org/FFmpeg/FFmpeg/pulls/25703 ↗
• https://github.com/FFmpeg/FFmpeg/commit/db98784a72600a94f7ebd5f016a37e01a505c27b ↗
• https://github.com/FFmpeg/FFmpeg/blob/n9.0.2/libavcodec/mlz.c#L161 ↗
• https://github.com/FFmpeg/FFmpeg ↗
• https://www.vulncheck.com/advisories/ffmpeg-through-9.0.2-uninitialized-heap-disclosure-via-mlz-decompressor-in-als-decoder ↗