---
id: "CVE-2026-118014"
kind: "vulnerability"
aliases: ["CVE-2026-118014"]
title: "Firefox: JavaScript JIT use-after-free can be triggered by crafted script"
severity: "unknown"
cvss: null
epss: null
exploited: false
status: "open"
category: "runtime"
products: []
ecosystems: []
tags: ["browser", "firefox", "runtime"]
not_affected_if: ["firefox-159-or-later"]
published_at: "2026-10-27T14:16:59+00:00"
first_seen_at: "2026-10-27T14:32:25+00:00"
updated_at: "2026-10-27T14:33:31+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-118014", "first_seen_at": "2026-10-27T14:32:25+00:00"}]
---

# Firefox: JavaScript JIT use-after-free can be triggered by crafted script

A use-after-free bug in the JIT compiler of Firefox's JavaScript engine lets memory be reused after it is freed. Per the sources it was fixed in Firefox 159; the sources do not state what an attacker can gain beyond that.

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

## How to check

- Check the installed Firefox version (`firefox --version`) and compare it with `159`
- unknown whether the sources list any other check

## Fix

- Update Firefox to `159` or later
- unknown whether the sources name any other action

## Timeline

- 2026-10-27T14:32:25+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-118014

## From the sources

Use-after-free in the JavaScript Engine: JIT component. This vulnerability was fixed in Firefox 159.

---

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