---
id: "CVE-2026-117997"
kind: "vulnerability"
aliases: ["CVE-2026-117997"]
title: "Firefox: use-after-free in Widget lets a sandbox escape"
severity: "unknown"
cvss: null
epss: null
exploited: false
status: "open"
category: "other"
products: []
ecosystems: []
tags: ["browser", "desktop", "firefox", "other"]
not_affected_if: ["no-firefox-installed"]
published_at: "2026-10-27T14:16:57+00:00"
first_seen_at: "2026-10-27T14:32:25+00:00"
updated_at: "2026-10-27T14:34:51+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-117997", "first_seen_at": "2026-10-27T14:32:25+00:00"}]
---

# Firefox: use-after-free in Widget lets a sandbox escape

A use-after-free bug in the Firefox Widget component allows escape from the browser sandbox. The sources do not say what an attacker gets after escaping or how the bug is triggered.

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

## How to check

- Run `firefox --version` or check Help > About Firefox and compare against the fixed versions
- unknown

## Fix

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

## Timeline

- 2026-10-27T14:32:25+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-117997

## From the sources

Sandbox escape due to use-after-free in the Widget component. This vulnerability was fixed in Firefox 159 and Firefox ESR 153.6.

---

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