High · CVSS 7.8CVE-2026-75141

FFmpeg Heap Buffer Overflow in hvcC Box Writer via HEVC Muxing

Answer in brief

CVE-2026-75141 records a High severity (CVSS 7.8) vulnerability in FFmpeg Heap Buffer Overflow in hvcC Box Writer via HEVC Muxing. 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 31, 2026Source checked Oct 4, 2026First seen by HOL Aug 19, 2026Material review Aug 31, 2026

Upstream Advisory

Key facts

Risk: High · CVSS 7.8
Exploitation: Not marked as known exploited
Affected software: 1 mapped package or product
Fix availability: Available

Why this deserves its current priority

CVSS is 7.8. 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 <acf5d7cdc1f9ae8752c23e1ea8d7f355ed780781	acf5d7cdc1f9ae8752c23e1ea8d7f355ed780781

Recommended response

Check inventory. Check lockfiles and deployed manifests for FFmpeg/FFmpeg.
Review the reported fix. Update FFmpeg/FFmpeg to acf5d7cdc1f9ae8752c23e1ea8d7f355ed780781 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 31, 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 acf5d7c contains a heap buffer overflow in the hvcC box writer. When writing an HEVC configuration record with more NAL units of a single type than the count field can represent, the NAL unit count overflows, causing a heap buffer overflow. A crafted HEVC input file triggers the overflow during muxing.

Quoted source text, attributed separately from HOL analysis.