---
id: "CVE-2026-117965"
kind: "vulnerability"
aliases: ["CVE-2026-117965"]
title: "Firefox: Address Bar flaw bypasses same-origin policy, fixed in 159"
severity: "unknown"
cvss: null
epss: null
exploited: false
status: "open"
category: "other"
products: []
ecosystems: []
tags: ["browsers", "desktop-users", "firefox", "other"]
not_affected_if: ["already-on-firefox-159-or-esr-153.6"]
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-2026-117965", "first_seen_at": "2026-10-27T14:32:24+00:00"}]
---

# Firefox: Address Bar flaw bypasses same-origin policy, fixed in 159

A flaw in the Firefox Address Bar component lets a page break the same-origin policy, which normally keeps one site from reading another site's data. The sources do not say what an attacker can read or how reliably it can be used.

_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
- unknown

## Fix

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

## Timeline

- 2026-10-27T14:32:24+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-117965

## From the sources

Same-origin policy bypass in the Address Bar component. This vulnerability was fixed in Firefox 159 and Firefox ESR 153.6.

---

_Free to read at a human pace. An API with keys and an MCP server are in preparation; early access: hello@infrastack.ai_