---
id: "CVE-2026-125238"
page: "https://infrastack.ai/live/CVE-2026-125238"
kind: "vulnerability"
aliases: ["CVE-2026-125238"]
title: "FFmpeg: crafted EVC file triggers assertion and aborts decoding"
severity: "medium"
cvss: 6.8
epss: null
exploited: false
status: "open"
category: "runtime"
products: []
ecosystems: []
tags: ["ffmpeg", "libavcodec", "media-pipelines", "runtime", "video-processing"]
not_affected_if: ["no-xevd-decoder", "trusted-input-only"]
published_at: "2026-11-09T19:17:02+00:00"
first_seen_at: "2026-11-09T19:28:20+00:00"
updated_at: "2026-11-09T19:30:24+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-125238", "first_seen_at": "2026-11-09T19:28:20+00:00"}]
exploit_sources: []
---

# FFmpeg: crafted EVC file triggers assertion and aborts decoding

Link for people: https://infrastack.ai/live/CVE-2026-125238 (this .md is for agents)

FFmpeg's libxevd decoder hits an av_assert0() when an EVC file has truncated or picture-less access units, because it returns success without producing a frame. An attacker who supplies such a file makes any application decoding it abort.

_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 build includes the libxevd (EVC) decoder, for example with `ffmpeg -decoders | grep -i xevd`.
- Find services that decode untrusted uploaded or streamed video with FFmpeg.

## Timeline

- 2026-11-09T19:28:20+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-125238

## Documents

- [advisory] Third-party advisory: www.vulncheck.com https://www.vulncheck.com/advisories/ffmpeg-through-9.0.2-reachable-assertion-in-libxevd-evc-decoder-wrapper
- [fix] Patch: github.com https://github.com/FFmpeg/FFmpeg/commit/33b0107a04b9ec361d76ae148cb6683964f88073

## From the sources

FFmpeg through 9.0.2 contains a reachable assertion vulnerability in libxevd_receive_frame() in libavcodec/libxevd.c that returns success when an access unit produces no frame. Attackers can supply a crafted EVC file with truncated or picture-less access units to trigger the av_assert0() on frame->private_ref, aborting any decoding application.

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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_