CVE-2026-75146
FFmpeg Out-of-Bounds Read in DASH Demuxer via dashdec.c
- State
- Published
- Severity
- 7.2 High
- Published
- Aug 19, 2026
- Updated
- Oct 27, 2026
- Reserved
- Aug 17, 2026
Description
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.
Scores
| CVSS | Score | Vector | Source |
|---|---|---|---|
| 4.0 | 7.2 High | CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:H/VI:N/VA:H/SC:N/SI:N/SA:N | VulnCheck |
| 3.1 | 8.1 High | CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:H | VulnCheck |
Weaknesses
- CWE-125 Out-of-bounds Read
Affected Products
| Product | Versions |
|---|---|
FFmpegFFmpeg |
|
References
- Pull Requestissue-tracking
- Patch Commitpatch
- https://www.vulncheck.com/advisories/ffmpeg-out-of-bounds-read-in-dash-demuxer-via-dashdec-cthird-party-advisory
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