---
id: "CVE-2026-125196"
page: "https://infrastack.ai/live/CVE-2026-125196"
kind: "vulnerability"
aliases: ["CVE-2026-125196"]
title: "FFmpeg: crafted mid-stream resolution change overflows heap in APV encoder"
severity: "high"
cvss: 7.3
epss: null
exploited: false
status: "open"
category: "runtime"
products: [{"name": "ffmpeg", "fixed": [], "affected": ">= 8.0, <= 9.0.2", "ecosystem": "vendor"}]
ecosystems: []
tags: ["ffmpeg", "liboapve", "media-transcoding", "runtime", "self-hosted"]
not_affected_if: ["no-apv-encoding", "no-liboapve", "trusted-input-only"]
published_at: "2026-11-09T19:16:55+00:00"
first_seen_at: "2026-11-09T19:28:17+00:00"
updated_at: "2026-11-09T19:34:52+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-125196", "first_seen_at": "2026-11-09T19:28:17+00:00"}, {"source": "analyst", "url": null, "first_seen_at": "2026-11-09T19:34:52+00:00"}]
exploit_sources: []
---

# FFmpeg: crafted mid-stream resolution change overflows heap in APV encoder

Link for people: https://infrastack.ai/live/CVE-2026-125196 (this .md is for agents)

FFmpeg through 9.0.2 has a heap buffer overflow in the liboapve encoder (libavcodec/liboapvenc.c) when frames are larger than the configured encoder dimensions. An attacker who supplies a video whose resolution changes mid-stream can corrupt heap memory while it is transcoded to APV without rescaling.

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

## Affected

- vendor:ffmpeg affected >= 8.0, <= 9.0.2 fixed no fixed version listed

## How to check

Run ffmpeg -version; builds 8.0 through 9.0.2 are affected. Run ffmpeg -encoders | grep apv: without liboapve the path is absent. Look for services transcoding untrusted video to APV without a scale filter. Until a release is confirmed, check whether your source includes the commit.

## Fix

No fixed release named in sources. Fix is upstream commit 87cdb6cd6a8d1ec201cb82b30e64d5f946939e23 (liboapvenc.c copies input using codec context dimensions); build from master with it or a release that includes it.

## Timeline

- 2026-11-09T19:28:17+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-125196
- 2026-11-09T19:34:52+00:00 analyst — Read commit 87cdb6cd and VulnCheck advisory (via WebFetch; web-cli out of credits). Affected FFmpeg >=8.0 through 9.0.2 per VulnCheck; no fixed release named, only the commit (encoder now copies using avctx dimensions). No exploitation or PoC stated. Release containing the fix unknown; check FFmpeg release notes/tags.

## Documents

- [advisory] Third-party advisory: www.vulncheck.com https://www.vulncheck.com/advisories/ffmpeg-through-9.0.2-heap-buffer-overflow-via-liboapv-apv-encoder-wrapper
- [fix] Patch: github.com https://github.com/FFmpeg/FFmpeg/commit/87cdb6cd6a8d1ec201cb82b30e64d5f946939e23

## From the sources

FFmpeg through 9.0.2 contains a heap buffer overflow vulnerability in liboapve_encode() in libavcodec/liboapvenc.c that allows attackers to corrupt heap memory by supplying frames larger than the configured encoder dimensions. Attackers can craft videos whose resolution changes mid-stream so that transcoding to APV without rescaling writes attacker-controlled pixel data past the imgb plane buffers.

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