CVE-2026-125103
LOW
NVD
CVSS Score
3.3
Severity
LOW
Published
Nov 09, 2026
Vendor
unknown
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.
References
- https://code.ffmpeg.org/FFmpeg/FFmpeg/pulls/25703
- https://github.com/FFmpeg/FFmpeg
- https://github.com/FFmpeg/FFmpeg/blob/n9.0.2/libavcodec/mlz.c#L161
- https://github.com/FFmpeg/FFmpeg/commit/db98784a72600a94f7ebd5f016a37e01a505c27b
- https://www.vulncheck.com/advisories/ffmpeg-through-9.0.2-uninitialized-heap-disclosure-via-mlz-decompressor-in-als-decoder