CVE-2025-6429
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.
Published:Jun 24, 2025
Last Modified:Apr 20, 2026
EPS:Jun 24, 2025
EPSS Score:0.00431
CVSS Score:6.5
Affected Products
Vendor
Product
Action
Vendor
Mozilla
Product
Firefox
Mozilla
Firefox
Vendor
Mozilla
Product
Firefox Esr
Mozilla
Firefox Esr
Vendor
Redhat
Product
Enterprise Linux
Redhat
Enterprise Linux
Vendor
Redhat
Product
Rhel Aus
Redhat
Rhel Aus
Vendor
Redhat
Product
Rhel E4s
Redhat
Rhel E4s
Vendor
Redhat
Product
Rhel Els
Redhat
Rhel Els
Vendor
Redhat
Product
Rhel Eus
Redhat
Rhel Eus
Vendor
Redhat
Product
Rhel Tus
Redhat
Rhel Tus
Exploits
No exploit reference
Common Weakness Enumeration
Common Attack Pattern Enumeration and Classification (CAPEC)
Related CVEs
References
Common Vulnerability Scoring System
Attack Vector
Network
Adjacent
Local
Physical
Privileges Required
None
Low
High
User Interaction
None
Required
Scope
Unchanged
Changed
Confidentiality
None
Low
High
Integrity
None
Low
High
Availability
None
Low
High
