CVE-2016-2817: Mozilla Firefox

Medium severity, CVSS 5.4. EPSS: 1.3% chance of exploitation in the next 30 days.

The WebExtension sandbox feature in browser/components/extensions/ext-tabs.js in Mozilla Firefox before 46.0 does not properly restrict principal inheritance during chrome.tabs.create and chrome.tabs.update API calls, which allows remote attackers to conduct Universal XSS (UXSS) attacks via a crafted extension that accesses a (1) javascript: or (2) data: URL.

Affected products

• Mozilla Firefox: up to and including 45.0.2

Published 2016-04-30. Last modified 2026-06-17.