Description
The exception page for the HTTPS-Only feature, displayed when a website is opened via HTTP, lacked an anti-clickjacking delay, potentially allowing an attacker to trick a user into granting an exception and loading a webpage over HTTP. This vulnerability was fixed in Firefox 140 and Thunderbird 140.
Scores
CVSS v3
4.3
EPSS
0.0017
EPSS Percentile
38.0%
Attack Vector
NETWORK
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:N
CISA SSVC
Vulnrichment
Exploitation
none
Automatable
no
Technical Impact
partial
Details
CWE
CWE-1021
Status
published
Products (3)
mozilla/firefox
< 140.0
Mozilla/Firefox
140
Mozilla/Thunderbird
140
Published
Jun 24, 2025
Tracked Since
Feb 18, 2026