Bug 2565035

Summary: CVE-2026-120246 ffmpeg: ffmpeg: Information disclosure via uninitialized palette entries in CDXL decoder [fedora-rawhide]
Product: [Fedora] Fedora Reporter: Marian Rehak <mrehak>
Component: ffmpegAssignee: Multimedia SIG <multimedia-sig>
Status: NEW --- QA Contact:
Severity: medium Docs Contact:
Priority: medium    
Version: rawhideCC: asn, development.group, dominik, multimedia-sig, ngompa13
Target Milestone: ---Keywords: Security, SecurityTracking
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Hardware: Unspecified   
OS: Unspecified   
Whiteboard: {"flaws": ["e07bc702-1bed-4127-abca-3f4638799726"]}
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oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
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Bug Depends On:    
Bug Blocks: 2564498    

Description Marian Rehak 2026-11-02 10:32:32 UTC 
Disclaimer: Community trackers are created by Red Hat Product Security team on a best effort basis. Package maintainers are required to ascertain if the flaw indeed affects their package, before starting the update process.

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.