---
id: "CVE-2026-117934"
kind: "vulnerability"
aliases: ["CVE-2026-117934"]
title: "Firefox: use-after-free in Layout component can be exploited"
severity: "unknown"
cvss: null
epss: null
exploited: false
status: "open"
category: "other"
products: []
ecosystems: []
tags: ["browsers", "desktops", "firefox", "other"]
not_affected_if: []
published_at: "2026-10-27T14:16:49+00:00"
first_seen_at: "2026-10-27T14:32:23+00:00"
updated_at: "2026-10-27T14:37:02+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-117934", "first_seen_at": "2026-10-27T14:32:23+00:00"}]
---

# Firefox: use-after-free in Layout component can be exploited

A use-after-free bug in the Layout component of Firefox can corrupt memory when a page is rendered. The sources do not say what an attacker gains beyond that, so the exact impact is not confirmed.

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

## How to check

- Check the installed Firefox version in the About Firefox page or with `firefox --version`, and compare it against 159, 115.44 and 153.6.
- Check whether ESR is in use on managed machines, since ESR branches are listed separately.

## Fix

- Update Firefox to `159` or later on the current channel.
- Update Firefox ESR to `115.44` or `153.6` on the ESR branches.

## Timeline

- 2026-10-27T14:32:23+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-117934

## 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.

---

_Free to read at a human pace. An API with keys and an MCP server are in preparation; early access: hello@infrastack.ai_