---
id: "CVE-2026-117901"
kind: "vulnerability"
aliases: ["CVE-2026-117901"]
title: "Firefox: use-after-free in DOM core lets page content crash or run code"
severity: "unknown"
cvss: null
epss: null
exploited: false
status: "open"
category: "package"
products: []
ecosystems: []
tags: ["desktop-browsers", "end-users", "firefox", "package"]
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: "2026-10-27T14:37:37+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-117901", "first_seen_at": "2026-10-27T14:32:22+00:00"}]
---

# Firefox: use-after-free in DOM core lets page content crash or run code

A use-after-free bug in the DOM Core and HTML component of Firefox reuses memory after it has been released. Sources do not say what an attacker can get beyond memory corruption, so the impact is unconfirmed.

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

## How to check

- Check the installed Firefox version in About Firefox or with the Firefox `--version` command
- Check ESR installs against `115.44` and `153.6` branches
- unknown for other checks

## Fix

- Update Firefox to `159` or later
- Update Firefox ESR 115 to `115.44` or later
- Update Firefox ESR 153 to `153.6` or later

## Timeline

- 2026-10-27T14:32:22+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-117901

## 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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