---
id: "CVE-2026-125263"
page: "https://infrastack.ai/live/CVE-2026-125263"
kind: "vulnerability"
aliases: ["CVE-2026-125263"]
title: "FFmpeg: crafted LCEVC streams force huge allocations and exhaust memory"
severity: "medium"
cvss: 5.7
epss: null
exploited: false
status: "open"
category: "runtime"
products: []
ecosystems: []
tags: ["ffmpeg", "media-processing", "runtime", "video-transcoding"]
not_affected_if: ["default-config", "trusted-input-only"]
published_at: "2026-11-09T20:18:12+00:00"
first_seen_at: "2026-11-09T20:48:13+00:00"
updated_at: "2026-11-09T20:49:56+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-125263", "first_seen_at": "2026-11-09T20:48:13+00:00"}]
exploit_sources: []
---

# FFmpeg: crafted LCEVC streams force huge allocations and exhaust memory

Link for people: https://infrastack.ai/live/CVE-2026-125263 (this .md is for agents)

FFmpeg 9.0 through 9.0.2 built with liblcevc_dec does not check LCEVC enhanced output dimensions against max_pixels before allocating frames. A crafted H.264, HEVC or VVC stream declaring a huge LCEVC resolution can force oversized buffer allocations and exhaust memory.

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

## How to check

- Run `ffmpeg -version` and check whether the version is `9.0` through `9.0.2`.
- Check whether the build includes liblcevc_dec, for example with `ffmpeg -decoders | grep -i lcevc`.

## Fix

- Move to a version later than `9.0.2` that is named in the patch linked from the NVD entry; the exact fixed version is unknown from the sources.

## Timeline

- 2026-11-09T20:48:13+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-125263

## Documents

- [advisory] Third-party advisory: www.vulncheck.com https://www.vulncheck.com/advisories/ffmpeg-9.0-through-9.0.2-memory-exhaustion-via-lcevc-enhancement-dimensions
- [fix] Patch: github.com https://github.com/FFmpeg/FFmpeg/commit/60b286521b46caa09792af04c6a4e3437aac8293

## From the sources

FFmpeg 9.0 through 9.0.2 built with liblcevc_dec fails to validate LCEVC enhanced output dimensions against max_pixels in libavcodec/decode.c before frame allocation. Attackers can supply crafted H.264, HEVC or VVC streams declaring huge LCEVC resolutions to force oversized get_buffer2() allocations and exhaust memory.

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