---
id: "CVE-2026-117945"
kind: "vulnerability"
aliases: ["CVE-2026-117945"]
title: "Firefox: XML component boundary bug fixed in versions 159 and ESR 153.6"
severity: "unknown"
cvss: null
epss: null
exploited: false
status: "open"
category: "other"
products: []
ecosystems: []
tags: ["browsers", "desktop", "firefox", "other"]
not_affected_if: []
published_at: "2026-10-27T14:16:50+00:00"
first_seen_at: "2026-10-27T14:32:23+00:00"
updated_at: "2026-10-27T14:35:43+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-117945", "first_seen_at": "2026-10-27T14:32:23+00:00"}]
---

# Firefox: XML component boundary bug fixed in versions 159 and ESR 153.6

Firefox's XML component has an incorrect boundary condition that Mozilla fixed in Firefox 159 and Firefox ESR 153.6. The sources do not say what an attacker gets from triggering it.

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

## How to check

- Check the installed Firefox version in the browser's About page or with `firefox --version`
- Check the ESR build with `firefox --version` on ESR installs, comparing against `153.6`

## Fix

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

## Timeline

- 2026-10-27T14:32:23+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-117945

## From the sources

Incorrect boundary conditions in the XML component. This vulnerability was fixed in Firefox 159 and Firefox ESR 153.6.

---

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