---
id: "CVE-2026-117967"
kind: "vulnerability"
aliases: ["CVE-2026-117967"]
title: "Firefox: DOM security component mitigation bypass, fixed in Firefox 159"
severity: "unknown"
cvss: null
epss: null
exploited: false
status: "open"
category: "runtime"
products: []
ecosystems: []
tags: ["browsers", "desktop", "firefox", "runtime"]
not_affected_if: ["already-on-fixed-version"]
published_at: "2026-10-27T14:16:54+00:00"
first_seen_at: "2026-10-27T14:32:24+00:00"
updated_at: "2026-10-27T14:35:22+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-117967", "first_seen_at": "2026-10-27T14:32:24+00:00"}]
---

# Firefox: DOM security component mitigation bypass, fixed in Firefox 159

A flaw in the DOM Security component of Firefox lets a page get around a security mitigation. The sources do not say what an attacker can do after bypassing it.

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

## How to check

- Run `firefox --version` or check About Firefox and compare against `159` or `153.6` for ESR.

## Fix

- Update Firefox to `159` or Firefox ESR to `153.6`.

## Timeline

- 2026-10-27T14:32:24+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-117967

## From the sources

Mitigation bypass in the DOM: Security component. This vulnerability was fixed in Firefox 159 and Firefox ESR 153.6.

---

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