---
id: "CVE-2026-117896"
kind: "vulnerability"
aliases: ["CVE-2026-117896"]
title: "Firefox: use-after-free in DOM core lets attacker run code"
severity: "unknown"
cvss: null
epss: null
exploited: false
status: "open"
category: "runtime"
products: []
ecosystems: []
tags: ["desktop-browsers", "end-users", "firefox", "runtime"]
not_affected_if: ["already-on-fixed-version"]
published_at: "2026-10-27T14:16:45+00:00"
first_seen_at: "2026-10-27T14:32:22+00:00"
updated_at: "2026-10-27T14:37:42+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-117896", "first_seen_at": "2026-10-27T14:32:22+00:00"}]
---

# Firefox: use-after-free in DOM core lets attacker run code

A use-after-free flaw in the DOM Core and HTML component of Firefox was fixed in Firefox 159 and Firefox ESR 115.44 and 153.6. The sources do not say what an attacker gains beyond the general memory-corruption risk.

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

## How to check

- Run `about:support` in Firefox and check the Application Basics version against `159`, `115.44` or `153.6`
- unknown for any other check, the sources do not say

## Fix

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

## Timeline

- 2026-10-27T14:32:22+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-117896

## From the sources

Use-after-free in the DOM: Core & HTML component. This vulnerability was fixed in Firefox 159, Firefox ESR 115.44, and Firefox ESR 153.6.

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