---
id: "CVE-2026-124307"
page: "https://infrastack.ai/live/CVE-2026-124307"
kind: "vulnerability"
aliases: ["CVE-2026-124307"]
title: "VVdeC: heap use-after-free in VVC decoder lets crafted bitstreams corrupt memory"
severity: "medium"
cvss: 5.8
epss: null
exploited: false
status: "open"
category: "package"
products: []
ecosystems: []
tags: ["c++", "package", "video-decoding", "vvc", "vvdec"]
not_affected_if: ["no-vvdec-usage", "single-threaded-decoding", "trusted-input-only"]
published_at: "2026-11-07T15:17:14+00:00"
first_seen_at: "2026-11-07T15:47:57+00:00"
updated_at: "2026-11-07T15:48:18+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-124307", "first_seen_at": "2026-11-07T15:47:57+00:00"}]
exploit_sources: []
---

# VVdeC: heap use-after-free in VVC decoder lets crafted bitstreams corrupt memory

Link for people: https://infrastack.ai/live/CVE-2026-124307 (this .md is for agents)

VVdeC, Fraunhofer HHI's VVC video decoder library, frees an ALF adaptation parameter set that slices still reference when a bitstream redefines it. With multithreaded decoding, worker threads then read the freed object, which can crash the decoder or corrupt heap memory.

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

## How to check

- Check the installed VVdeC version: `unknown` if the sources do not name a command; look for VVdeC in your dependency manifests or build files
- Check whether you decode untrusted VVC bitstreams with multithreaded decoding enabled

## Fix

- VVdeC: `3.2.1` (fix is stated as 'before 3.2.1' in the product range)

## Timeline

- 2026-11-07T15:47:57+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-124307

## Documents

- [advisory] Third-party advisory: www.vulncheck.com https://www.vulncheck.com/advisories/fraunhofer-hhi-vvdec-before-3.2.1-heap-use-after-free-via-alf-aps-redefinition
- [fix] Patch: github.com https://github.com/fraunhoferhhi/vvdec/commit/1eddb30c4b8e02f3d13ba24aa7e52f1aa7b08c01

## From the sources

Fraunhofer HHI VVdeC before 3.2.1 contains a heap use-after-free vulnerability that allows attackers to corrupt memory by redefining an ALF adaptation parameter set id still referenced by slices. Attackers can supply a crafted VVC bitstream that, with multithreaded decoding, makes worker threads dereference freed APS objects in CABACReader::readAlf() and AdaptiveLoopFilter::reconstructCoeff(), causing crashes or heap corruption.

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