---
id: "CVE-2026-125187"
page: "https://infrastack.ai/live/CVE-2026-125187"
kind: "vulnerability"
aliases: ["CVE-2026-125187"]
title: "FFmpeg: crafted audio makes TTA encoding abort the application"
severity: "medium"
cvss: 6.8
epss: null
exploited: false
status: "open"
category: "runtime"
products: []
ecosystems: []
tags: ["ffmpeg", "libavcodec", "media-transcoding", "runtime"]
not_affected_if: ["no-tta-encoding", "no-untrusted-audio"]
published_at: "2026-11-09T19:16:54+00:00"
first_seen_at: "2026-11-09T19:28:17+00:00"
updated_at: "2026-11-09T19:31:34+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-125187", "first_seen_at": "2026-11-09T19:28:17+00:00"}]
exploit_sources: []
---

# FFmpeg: crafted audio makes TTA encoding abort the application

Link for people: https://infrastack.ai/live/CVE-2026-125187 (this .md is for agents)

FFmpeg's TTA audio encoder fails to reserve space for a 4-byte CRC in its output packet. A crafted audio input can trigger an assertion that aborts the process transcoding to TTA, causing a denial of service.

_Summary, check and fix written by a model from the sources; labelled as such._

## How to check

- Run `ffmpeg -version` and compare against the fixed release in the sources
- Check whether your pipeline transcodes audio to TTA (`-c:a tta`)

## Timeline

- 2026-11-09T19:28:17+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-125187

## Documents

- [advisory] Third-party advisory: www.vulncheck.com https://www.vulncheck.com/advisories/ffmpeg-through-9.0.2-tta-encoder-reachable-assertion-via-tta-encode-frame
- [fix] Patch: github.com https://github.com/FFmpeg/FFmpeg/commit/29a629e788c4343ff2e923095b8f38769fe2e470

## From the sources

FFmpeg through 9.0.2 contains a reachable assertion vulnerability in the TTA encoder's tta_encode_frame() in libavcodec/ttaenc.c, which never reserves output packet space for the 4-byte CRC. Attackers can supply audio whose sample values and length produce a small, poorly compressible final frame, triggering the av_assert0() in flush_put_bits() and aborting applications transcoding to TTA.

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_Free to read, with fair use of about 60 pages a minute. For higher limits or API access: sales@infrastack.ai_