CVE-2017-5466: Mozilla Firefox

Medium severity, CVSS 6.1. EPSS: 1.5% chance of exploitation in the next 30 days.

If a page is loaded from an original site through a hyperlink and contains a redirect to a "data:text/html" URL, triggering a reload will run the reloaded "data:text/html" page with its origin set incorrectly. This allows for a cross-site scripting (XSS) attack. This vulnerability affects Thunderbird < 52.1, Firefox ESR < 52.1, and Firefox < 53.

Affected products

• Mozilla Firefox: before 53.0 (fixed in 53.0); before 52.1.0 (fixed in 52.1.0)
• Mozilla Thunderbird: before 52.1.0 (fixed in 52.1.0)
• Red Hat Enterprise Linux: version 6.0 only; version 7.0 only
• Red Hat Enterprise Linux Desktop: version 6.0 only; version 7.0 only
• Red Hat Enterprise Linux Server: version 6.0 only; version 7.0 only
• Red Hat Enterprise Linux Server Aus: version 7.3 only; version 7.4 only
• Red Hat Enterprise Linux Server Eus: version 7.3 only; version 7.4 only; version 7.5 only
• Red Hat Enterprise Linux Workstation: version 6.0 only; version 7.0 only

Published 2018-06-11. Last modified 2026-06-17.