---
id: "CVE-2026-117938"
kind: "vulnerability"
aliases: ["CVE-2026-117938"]
title: "Firefox: use-after-free in Layout component can crash or corrupt memory"
severity: "unknown"
cvss: null
epss: null
exploited: false
status: "open"
category: "runtime"
products: []
ecosystems: []
tags: ["browser", "desktop", "firefox", "runtime"]
not_affected_if: []
published_at: "2026-10-27T14:16:49+00:00"
first_seen_at: "2026-10-27T14:32:23+00:00"
updated_at: "2026-10-27T14:36:58+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-117938", "first_seen_at": "2026-10-27T14:32:23+00:00"}]
---

# Firefox: use-after-free in Layout component can crash or corrupt memory

A use-after-free bug in the Layout component of Firefox lets memory be reused after it is released. The sources do not say what an attacker can do beyond that, and the fix is in Firefox 159 and Firefox ESR 115.44 and ESR 153.6.

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

## How to check

- Check the installed Firefox version (Help > About Firefox, or `firefox --version`) and compare it to `159`, `115.44` (ESR) or `153.6` (ESR).
- unknown whether the sources list other check steps.

## Fix

- Update Firefox to `159` or later.
- Update Firefox ESR to `115.44` or `153.6`, depending on the ESR branch in use.

## Timeline

- 2026-10-27T14:32:23+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-117938

## 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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