---
id: "CVE-2026-117867"
kind: "vulnerability"
aliases: ["CVE-2026-117867"]
title: "Firefox: use-after-free in Layout component can crash or run code"
severity: "unknown"
cvss: null
epss: null
exploited: false
status: "open"
category: "runtime"
products: []
ecosystems: []
tags: ["browsers", "desktop", "firefox", "runtime"]
not_affected_if: ["already-on-fixed-version"]
published_at: "2026-10-27T14:16:41+00:00"
first_seen_at: "2026-10-27T14:32:21+00:00"
updated_at: "2026-10-27T14:39:18+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-117867", "first_seen_at": "2026-10-27T14:32:21+00:00"}]
---

# Firefox: use-after-free in Layout component can crash or run code

Firefox's Layout component has a use-after-free bug, where memory is used after it has been released. The sources do not say what an attacker can gain beyond that, but memory corruption like this can be used to crash the browser or run attacker code.

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

## How to check

- Run `firefox --version` and compare against the fixed releases `159`, `115.44` and `153.6` (ESR)
- Check the Help > About Firefox page for the installed version

## Fix

- Update Firefox to `159` or later
- Update Firefox ESR to `115.44` or `153.6`

## Timeline

- 2026-10-27T14:32:21+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-117867

## From the sources

Use-after-free in the Layout component. This vulnerability was fixed in Firefox 159, Firefox ESR 115.44, and Firefox ESR 153.6.

---

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