{"id":"CVE-2026-125103","title":"FFmpeg through 9.0.2 Uninitialized Heap Disclosure via MLZ Decompressor in ALS Decoder","summary":"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 m…","severity":"low","cvss":3.3,"cvssVector":"CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:N","cvssSource":"cna","cwe":["CWE-908"],"vendor":"FFmpeg","product":"FFmpeg","affected":["FFmpeg <= 9.0.2"],"published":"2026-11-09","updated":"2026-11-09","sourceUpdated":"2026-11-09T19:10:57.722Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-125103","references":[{"url":"https://code.ffmpeg.org/FFmpeg/FFmpeg/pulls/25703"},{"url":"https://github.com/FFmpeg/FFmpeg/commit/db98784a72600a94f7ebd5f016a37e01a505c27b","label":"Patch Commit"},{"url":"https://github.com/FFmpeg/FFmpeg/blob/n9.0.2/libavcodec/mlz.c#L161"},{"url":"https://github.com/FFmpeg/FFmpeg"},{"url":"https://www.vulncheck.com/advisories/ffmpeg-through-9.0.2-uninitialized-heap-disclosure-via-mlz-decompressor-in-als-decoder","label":"VulnCheck Advisory: FFmpeg through 9.0.2 Uninitialized Heap Disclosure via MLZ Decompressor in ALS Decoder"}],"tags":["cve.org"],"ingestedAt":"2026-11-09T19:18:02.628Z","slug":"CVE-2026-125103","body":"## Overview\n\nFFmpeg 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.\n\n## Affected\n\n- `FFmpeg <= 9.0.2`\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"sunlit","depthScore":18,"depthScoreParts":{"impact":18.2,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}