An attacker was able to bypass the `connect-src` directive of a Content Security Policy by manipulating subdocuments. This would have also hidden the connections from the Network tab in Devtools. This vulnerability was fixed in Firefox 140 and Thunderbird 140.
History

Mon, 13 Apr 2026 15:00:00 +0000

Type Values Removed Values Added
Description An attacker was able to bypass the `connect-src` directive of a Content Security Policy by manipulating subdocuments. This would have also hidden the connections from the Network tab in Devtools. This vulnerability affects Firefox < 140 and Thunderbird < 140. An attacker was able to bypass the `connect-src` directive of a Content Security Policy by manipulating subdocuments. This would have also hidden the connections from the Network tab in Devtools. This vulnerability was fixed in Firefox 140 and Thunderbird 140.

Thu, 30 Oct 2025 16:30:00 +0000

Type Values Removed Values Added
Title firefox: connect-src Content Security Policy restriction could be bypassed connect-src Content Security Policy restriction could be bypassed

Tue, 15 Jul 2025 13:45:00 +0000

Type Values Removed Values Added
Metrics epss

{'score': 0.00055}

epss

{'score': 0.00052}


Mon, 14 Jul 2025 18:45:00 +0000

Type Values Removed Values Added
Description An attacker was able to bypass the `connect-src` directive of a Content Security Policy by manipulating subdocuments. This would have also hidden the connections from the Network tab in Devtools. This vulnerability affects Firefox < 140. An attacker was able to bypass the `connect-src` directive of a Content Security Policy by manipulating subdocuments. This would have also hidden the connections from the Network tab in Devtools. This vulnerability affects Firefox < 140 and Thunderbird < 140.
References

Thu, 03 Jul 2025 17:00:00 +0000

Type Values Removed Values Added
First Time appeared Mozilla
Mozilla firefox
CPEs cpe:2.3:a:mozilla:firefox:*:*:*:*:-:*:*:*
Vendors & Products Mozilla
Mozilla firefox

Thu, 26 Jun 2025 00:30:00 +0000

Type Values Removed Values Added
Title firefox: connect-src Content Security Policy restriction could be bypassed
References
Metrics threat_severity

None

threat_severity

Moderate


Wed, 25 Jun 2025 15:15:00 +0000

Type Values Removed Values Added
Weaknesses CWE-693
Metrics cvssV3_1

{'score': 9.1, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N'}

ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'none', 'Technical Impact': 'total'}, 'version': '2.0.3'}


Tue, 24 Jun 2025 12:45:00 +0000

Type Values Removed Values Added
Description An attacker was able to bypass the `connect-src` directive of a Content Security Policy by manipulating subdocuments. This would have also hidden the connections from the Network tab in Devtools. This vulnerability affects Firefox < 140.
References

cve-icon MITRE

Status: PUBLISHED

Assigner: mozilla

Published: 2025-06-24T12:28:01.317Z

Updated: 2026-04-13T14:31:00.300Z

Reserved: 2025-06-20T14:51:31.244Z

Link: CVE-2025-6427

cve-icon Vulnrichment

Updated: 2025-06-25T14:21:00.484Z

cve-icon NVD

Status : Modified

Published: 2025-06-24T13:15:23.650

Modified: 2026-04-13T15:17:06.703

Link: CVE-2025-6427

cve-icon Redhat

Severity : Moderate

Publid Date: 2025-06-24T12:28:01Z

Links: CVE-2025-6427 - Bugzilla