CVE-2017-5466
Mozilla: Origin confusion when reloading isolated data:text/html URL (MFSA 2017-12)
Severity
CriticalRed Hat Product Security
CVSS 3.0
Review impact separately from score.
Published · April 19, 2017
Updated · November 26, 2025
Description
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.
CVSS score applicability
The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.
Mitigation
No mitigation is specified in collected source.
CVSS / CWE
CVSS 3.0 · 6.1CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
CWE not specified