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.
Published: 2026-08-19
Score: 7.2 High
EPSS: n/a
KEV: No
Impact: n/a
Action: n/a
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Remediation

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History

Wed, 19 Aug 2026 16:45:00 +0000

Type Values Removed Values Added
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.
Title FFmpeg Out-of-Bounds Read in DASH Demuxer via dashdec.c
Weaknesses CWE-125
References
Metrics cvssV3_1

{'score': 8.1, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:H'}

cvssV4_0

{'score': 7.2, 'vector': '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'}

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cve-icon MITRE

Status: PUBLISHED

Assigner: VulnCheck

Published:

Updated: 2026-08-19T16:28:19.356Z

Reserved: 2026-08-17T18:39:57.662Z

Link: CVE-2026-75146

cve-icon Vulnrichment

No data.

cve-icon NVD

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cve-icon Redhat

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cve-icon OpenCVE Enrichment

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Weaknesses