FFmpeg Out-of-Bounds Read in DASH Demuxer via dashdec.c (CVE-2026-75146) | HOL Guard CVE

Unknown severity · Source severity not reportedCVE-2026-75146

FFmpeg Out-of-Bounds Read in DASH Demuxer via dashdec.c

Answer in brief

CVE-2026-75146 records a Unknown severity vulnerability in FFmpeg Out-of-Bounds Read in DASH Demuxer via dashdec.c. The current sources do not mark it as known exploited. The current feed maps FFmpeg/FFmpeg (generic). Check affected ranges and fixed versions before updating.

Analysis pending evidence review

HOL Guard separates source facts from reviewed analysis. See the methodology.

Published Aug 19, 2026Updated Aug 19, 2026Source checked Aug 19, 2026First seen by HOL Aug 19, 2026Material review Aug 19, 2026

Upstream Advisory

Key facts

Risk: Unknown severitySource severity not reported
Exploitation: Not marked as known exploited
Affected software: 1 mapped package or product
Fix availability: Available

Why this deserves its current priority

A CVSS score is not reported in the current record. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.

Analysis status

Analysis pending evidence review

Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.

Affected scope and exposure questions

The current feed maps FFmpeg/FFmpeg (generic). Check affected ranges and fixed versions before updating.

Mapped affected packages and fixed versions
Package	Affected range	Fixed version
FFmpeg/FFmpeggeneric	>=0 <65b0dab903e5975e036b30ecc58f5935d4f151e0	65b0dab903e5975e036b30ecc58f5935d4f151e0

Recommended response

Check inventory. Check lockfiles and deployed manifests for FFmpeg/FFmpeg.
Review the reported fix. Update FFmpeg/FFmpeg to 65b0dab903e5975e036b30ecc58f5935d4f151e0 if you use the affected versions. Test the change in a non-production environment first.

Evidence timeline and material changes

Published upstream
Aug 19, 2026
Evidence: source:cvelist:source_dates:source-dates:record
Source modified
Aug 19, 2026
Evidence: source:cvelist:source_dates:source-dates:record
First seen by HOL
Aug 19, 2026

Sources and claim methodology

Upstream source 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.

Quoted source text, attributed separately from HOL analysis.