Description
Firefox could have incorrectly parsed a URL and rewritten it to the youtube.com domain when parsing the URL specified in an `embed` tag. This could have bypassed website security checks that restricted which domains users were allowed to embed. This vulnerability was fixed in Firefox 140, Firefox ESR 128.12, Thunderbird 140, and Thunderbird 128.12.
References (7)
Scores
CVSS v3
6.5
EPSS
0.0043
EPSS Percentile
62.7%
Attack Vector
NETWORK
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:N
CISA SSVC
Vulnrichment
Exploitation
none
Automatable
no
Technical Impact
partial
Details
CWE
CWE-116
Status
published
Products (6)
mozilla/firefox
< 128.12.0
mozilla/firefox
< 140.0
Mozilla/Firefox
128.12 - 128.*
Mozilla/Firefox
140
Mozilla/Thunderbird
128.12 - 128.*
Mozilla/Thunderbird
140
Published
Jun 24, 2025
Tracked Since
Feb 18, 2026