Bug 2525516

Summary: CVE-2026-75146 ffmpeg: FFmpeg: Information disclosure and denial of service via out-of-bounds read in DASH demuxer [epel-all]
Product: [Fedora] Fedora EPEL Reporter: Thibault Guittet <tguittet>
Component: ffmpegAssignee: Multimedia SIG <multimedia-sig>
Status: NEW --- QA Contact:
Severity: high Docs Contact:
Priority: high    
Version: epel10CC: asn, dominik, multimedia-sig, ngompa13, philip.wyett
Target Milestone: ---Keywords: Security, SecurityTracking
Target Release: ---   
Hardware: Unspecified   
OS: Unspecified   
Whiteboard: {"flaws": ["e6664afd-deff-4a9d-9e0e-5791d202ecef"]}
Fixed In Version: Doc Type: ---
Doc Text:
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Clone Of: Environment:
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Regression: --- Mount Type: ---
Documentation: --- CRM:
Verified Versions: Category: ---
oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:
Embargoed:
Bug Depends On:    
Bug Blocks: 2519764    

Description Thibault Guittet 2026-08-28 09:14:45 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 before commit 65b0dab contains an out-of-bounds read in the DASH demuxer (libavformat/dashdec.c). When a live DASH manifest is refreshed with a startNumber that is lower than the previous value, the current sequence number is driven negative. The fragment retrieval function checked only the upper bound before indexing the fragments array, allowing a negative index to be used and causing an out-of-bounds read. A malicious or misconfigured DASH server can trigger this by serving a live manifest with a decreasing startNumber across a manifest refresh.