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 affects Firefox < 140, Firefox ESR < 128.12, Thunderbird < 140, and Thunderbird < 128.12.

CVSS v3 6.5 MEDIUM

6.5^/10

CVSS v3 : MEDIUM

Vector :

Exploitability : 2.8 / Impact : 3.6

Attack Vector NETWORK

Attack Complexity LOW

Privileges Required NONE

User Interaction REQUIRED

Confidentiality Impact NONE

Integrity Impact HIGH

Availability Impact NONE

Scope UNCHANGED

References

Link	Resource
https://bugzilla.mozilla.org/show_bug.cgi?id=1970658	Permissions Required
https://www.mozilla.org/security/advisories/mfsa2025-51/	Vendor Advisory
https://www.mozilla.org/security/advisories/mfsa2025-53/	Vendor Advisory
https://www.mozilla.org/security/advisories/mfsa2025-54/
https://www.mozilla.org/security/advisories/mfsa2025-55/
https://lists.debian.org/debian-lts-announce/2025/06/msg00029.html
https://lists.debian.org/debian-lts-announce/2025/07/msg00002.html

Configurations

Configuration 1 (hide)

OR	cpe:2.3:a:mozilla:firefox:::::esr:::*
	cpe:2.3:a:mozilla:firefox:::::-:::*

History

03 Nov 2025, 20:19

Type	Values Removed	Values Added
References		() https://lists.debian.org/debian-lts-announce/2025/06/msg00029.html - () https://lists.debian.org/debian-lts-announce/2025/07/msg00002.html -

Information

Published : 2025-06-24 13:15

Updated : 2025-11-03 20:19

NVD link : CVE-2025-6429

Mitre link : CVE-2025-6429

CVE.ORG link : CVE-2025-6429

JSON object : View

Products Affected

mozilla

firefox

CWE

CWE-116

Improper Encoding or Escaping of Output

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