Bug 2525517

Summary: CVE-2026-75146 ffmpeg: FFmpeg: Information disclosure and denial of service via out-of-bounds read in DASH demuxer [fedora-43]
Product: [Fedora] Fedora Reporter: Thibault Guittet <tguittet>
Component: ffmpegAssignee: Multimedia SIG <multimedia-sig>
Status: ON_QA --- QA Contact:
Severity: high Docs Contact:
Priority: high    
Version: 43CC: asn, development.group, dominik, multimedia-sig, ngompa13
Target Milestone: ---Keywords: Security, SecurityTracking
Target Release: ---   
Hardware: Unspecified   
OS: Unspecified   
Whiteboard: {"flaws": ["e6664afd-deff-4a9d-9e0e-5791d202ecef"]}
Fixed In Version: ffmpeg-9.0.1-1.fc46,ffmpeg-9.0.1-4.fc45,ffmpeg-8.1.3-1.fc44 Doc Type: ---
Doc Text:
Story Points: ---
Clone Of: Environment:
Last Closed: Type: ---
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 09:14:49 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.
Comment 1 Dominik 'Rathann' Mierzejewski 2026-09-18 14:54:08 UTC 
This is fixed in:
9.0.1: https://code.ffmpeg.org/FFmpeg/FFmpeg/commit/999f8ba75ce0bf1167677de7e11a5af678fdb866

So only F44 and older are affected.
Comment 2 Dominik 'Rathann' Mierzejewski 2026-09-28 16:48:50 UTC 
8.1.3: https://code.ffmpeg.org/FFmpeg/FFmpeg/commit/62d4ca1f3ead52ac45c9ceae761e0139f42bfd4b
Comment 3 Fedora Update System 2026-09-28 16:49:13 UTC 
FEDORA-2026-3e109a0c85 (ffmpeg-8.1.3-1.fc44) has been submitted as an update to Fedora 44.
https://bodhi.fedoraproject.org/updates/FEDORA-2026-3e109a0c85
Comment 4 Fedora Update System 2026-09-29 02:11:21 UTC 
FEDORA-2026-3e109a0c85 has been pushed to the Fedora 44 testing repository.
Soon you'll be able to install the update with the following command:
`sudo dnf upgrade --enablerepo=updates-testing --refresh --advisory=FEDORA-2026-3e109a0c85`
You can provide feedback for this update here: https://bodhi.fedoraproject.org/updates/FEDORA-2026-3e109a0c85

See also https://fedoraproject.org/wiki/QA:Updates_Testing for more information on how to test updates.
Comment 5 Dominik 'Rathann' Mierzejewski 2026-09-29 09:55:00 UTC 
NOT fixed in 7.1.x.