Vulnerability Description
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 select unfilled new_palette entries in cdxl_decode_ham8() or cdxl_decode_ham6(), exposing stack bytes and pointer fragments in the BGR24 output.
CVSS Score
MEDIUM
Related Weaknesses (CWE)
References
- https://code.ffmpeg.org/FFmpeg/FFmpeg/pulls/24856
- https://github.com/FFmpeg/FFmpeg
- https://github.com/FFmpeg/FFmpeg/blob/n9.0.2/libavcodec/cdxl.c#L226-L229
- https://github.com/FFmpeg/FFmpeg/commit/47313ad3f9f33b892384b976fb7c09b3c85fd74e
- https://www.vulncheck.com/advisories/ffmpeg-4.4-through-9.0.2-uninitialized-memo
FAQ
What is CVE-2026-120246?
CVE-2026-120246 is a vulnerability with a CVSS score of 5.5 (MEDIUM). 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 ...
How severe is CVE-2026-120246?
CVE-2026-120246 has been rated MEDIUM with a CVSS base score of 5.5/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2026-120246?
Check the references section above for vendor advisories and patch information. Review vendor security bulletins for remediation guidance.