CVE-2025-6429

  1. OpenCVE
  2. Vulnerabilities (CVE)
  3. 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.

6.5 /10

CVSS v3 : MEDIUM

V3 Legend

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

13 Apr 2026, 15:17

Type Values Removed Values Added
Summary (en) 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. (en) 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.

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 -

14 Jul 2025, 19:15

Type Values Removed Values Added
References
  • () https://www.mozilla.org/security/advisories/mfsa2025-54/ -
  • () https://www.mozilla.org/security/advisories/mfsa2025-55/ -
Summary (en) 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 and Firefox ESR < 128.12. (en) 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.

03 Jul 2025, 16:43

Type Values Removed Values Added
References () https://bugzilla.mozilla.org/show_bug.cgi?id=1970658 - () https://bugzilla.mozilla.org/show_bug.cgi?id=1970658 - Permissions Required
References () https://www.mozilla.org/security/advisories/mfsa2025-51/ - () https://www.mozilla.org/security/advisories/mfsa2025-51/ - Vendor Advisory
References () https://www.mozilla.org/security/advisories/mfsa2025-53/ - () https://www.mozilla.org/security/advisories/mfsa2025-53/ - Vendor Advisory
CPE cpe:2.3:a:mozilla:firefox:*:*:*:*:-:*:*:*
cpe:2.3:a:mozilla:firefox:*:*:*:*:esr:*:*:*
First Time Mozilla firefox
Mozilla

25 Jun 2025, 15:15

Type Values Removed Values Added
Summary
  • (es) Firefox podría haber analizado incorrectamente una URL y reescrito el dominio youtube.com al analizar la URL especificada en una etiqueta `embed`. Esto podría haber eludido las comprobaciones de seguridad del sitio web que restringían los dominios que los usuarios podían incrustar. Esta vulnerabilidad afecta a Firefox con versiones anteriores a 140 y Firefox con ESR inferior a 128.12.
CWE CWE-116
CVSS v2 : unknown
v3 : unknown 		v2 : unknown
v3 : 6.5

24 Jun 2025, 13:15

Type Values Removed Values Added
New CVE
Information

Published : 2025-06-24 13:15

Updated : 2026-04-13 15:17

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