---
id: "CVE-2026-118026"
kind: "vulnerability"
aliases: ["CVE-2026-118026"]
title: "Firefox: invalid pointer in JavaScript garbage collector fixed in 159"
severity: "unknown"
cvss: null
epss: null
exploited: false
status: "open"
category: "runtime"
products: []
ecosystems: []
tags: ["browser-users", "desktop", "firefox", "runtime"]
not_affected_if: ["firefox-159-or-later"]
published_at: "2026-10-27T14:17:00+00:00"
first_seen_at: "2026-10-27T14:32:25+00:00"
updated_at: "2026-10-27T14:33:18+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-118026", "first_seen_at": "2026-10-27T14:32:25+00:00"}]
---

# Firefox: invalid pointer in JavaScript garbage collector fixed in 159

Firefox's JavaScript garbage collector can use an invalid pointer, a memory-safety bug. The sources do not say what an attacker can achieve beyond that, so the impact is unconfirmed.

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

## How to check

- `Help > About Firefox` in the browser shows the installed version; a version below `159` is affected
- Enterprise fleets: check the Firefox version reported by the device management tool

## Fix

- Update Firefox to `159` or later

## Timeline

- 2026-10-27T14:32:25+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-118026

## From the sources

Invalid pointer in the JavaScript: GC component. This vulnerability was fixed in Firefox 159.

---

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