{"id":"CVE-2026-120246","title":"FFmpeg 4.4 through 9.0.2 Uninitialized Memory Disclosure via CDXL HAM Decoder","summary":"FFmpeg 4.4 through 9.0.2 contains a use of uninitialized variable vulnerability in the CDXL decoder that leaks stack memory into decoded pixels via unfilled HAM palette entries. Attackers can craft a type-0 CDXL file whose HAM pixels sel…","severity":"medium","cvss":5.5,"cvssVector":"CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N","cvssSource":"cna","cwe":["CWE-457"],"vendor":"FFmpeg","product":"FFmpeg","affected":["FFmpeg >= 4.4 <= 9.0.2"],"ssvc":{"exploitation":"none","automatable":"no","technicalImpact":"partial","timestamp":"2026-11-05T15:37:33.214014Z"},"published":"2026-11-01","updated":"2026-11-05","sourceUpdated":"2026-11-05T15:37:47.734Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-120246","references":[{"url":"https://code.ffmpeg.org/FFmpeg/FFmpeg/pulls/24856"},{"url":"https://github.com/FFmpeg/FFmpeg/commit/47313ad3f9f33b892384b976fb7c09b3c85fd74e"},{"url":"https://github.com/FFmpeg/FFmpeg/blob/n9.0.2/libavcodec/cdxl.c#L226-L229"},{"url":"https://github.com/FFmpeg/FFmpeg"},{"url":"https://www.vulncheck.com/advisories/ffmpeg-4.4-through-9.0.2-uninitialized-memory-disclosure-via-cdxl-ham-decoder","label":"VulnCheck Advisory: FFmpeg 4.4 through 9.0.2 Uninitialized Memory Disclosure via CDXL HAM Decoder"}],"tags":["cve.org"],"epss":0.00124,"epssPercentile":0.02128,"ingestedAt":"2026-11-05T21:36:00.910Z","slug":"CVE-2026-120246","body":"## Overview\n\nFFmpeg 4.4 through 9.0.2 contains a use of uninitialized variable vulnerability in the CDXL decoder that leaks stack memory into decoded pixels via unfilled HAM palette entries. Attackers can craft a type-0 CDXL file whose HAM pixels select unfilled new_palette entries in cdxl_decode_ham8() or cdxl_decode_ham6(), exposing stack bytes and pointer fragments in the BGR24 output.\n\n## Affected\n\n- `FFmpeg >= 4.4 <= 9.0.2`\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"sunlit","depthScore":30,"depthScoreParts":{"impact":30.3,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}