---
id: "CVE-2026-124861"
page: "https://infrastack.ai/live/CVE-2026-124861"
kind: "vulnerability"
aliases: ["CVE-2026-124861"]
title: "Firefox: use-after-free in audio component lets sandbox be escaped"
severity: "high"
cvss: null
epss: null
exploited: false
status: "open"
category: "runtime"
products: [{"name": "Firefox", "fixed": [], "affected": "", "ecosystem": "runtime"}]
ecosystems: ["runtime"]
tags: ["browsers", "desktop", "firefox", "runtime"]
not_affected_if: ["up-to-date-firefox"]
published_at: "2026-11-10T14:17:18+00:00"
first_seen_at: "2026-11-10T14:22:13+00:00"
updated_at: "2026-11-10T14:26:36+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-124861", "first_seen_at": "2026-11-10T14:22:13+00:00"}]
exploit_sources: []
---

# Firefox: use-after-free in audio component lets sandbox be escaped

Link for people: https://infrastack.ai/live/CVE-2026-124861 (this .md is for agents)

A use-after-free bug in Firefox's Audio/Video cubeb component allows a sandbox escape. A successful attack lets malicious code get past the browser's sandbox protections.

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

## Affected

- runtime:Firefox affected range not listed fixed no fixed version listed

## How to check

- Check the Firefox version with `about:support` or Help > About Firefox.
- Confirm it is below `160` on the current branch, below `153.7` on ESR 153, or below `115.45` on ESR 115.

## Fix

- Firefox: `160`
- Firefox ESR: `115.45`
- Firefox ESR: `153.7`

## Timeline

- 2026-11-10T14:22:13+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-124861

## From the sources

Sandbox escape due to use-after-free in the Audio/Video: cubeb component. This vulnerability was fixed in Firefox 160, Firefox ESR 115.45, and Firefox ESR 153.7.

---

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