CVE-2025-6427
9.1 · CRITICALOverview
CVE-2025-6427 is a critical-severity vulnerability affecting mozilla firefox. It was published on June 24, 2025 and has a CVSS 3.1 base score of 9.1 (CRITICAL).
This vulnerability has a CVSS 3.1 base score of 9.1, rated CRITICAL. It can be exploited remotely over the network. No authentication or special privileges are required for exploitation.
Technical 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 was fixed in Firefox 140 and Thunderbird 140.
Remediation
Check the references section for vendor advisories and patches from mozilla. Update firefox to the latest patched version. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.
Affected Products
| Vendor | Product | Versions | Status |
|---|---|---|---|
| mozilla | firefox | >= 0, < 140.0 | Affected |
Frequently Asked Questions
What is CVE-2025-6427?
CVE-2025-6427 is a critical-severity vulnerability affecting mozilla firefox. It was published on June 24, 2025 and has a CVSS 3.1 base score of 9.1 (CRITICAL).
How severe is CVE-2025-6427?
This vulnerability has a CVSS 3.1 base score of 9.1, rated CRITICAL. It can be exploited remotely over the network. No authentication or special privileges are required for exploitation.
How do I fix or remediate CVE-2025-6427?
Check the references section for vendor advisories and patches from mozilla. Update firefox to the latest patched version. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.
How can CyberStrike help with CVE-2025-6427?
CyberStrike's AI-powered security agents can automatically detect CVE-2025-6427 across your infrastructure using autonomous pentesting, DAST scanning, and HackBrowser. The platform continuously monitors for known vulnerabilities and provides actionable remediation guidance prioritized by real-world exploitability.
How CyberStrike Helps
AI agents map your attack surface to find vulnerabilities like this one.
Automated penetration testing that runs continuously, not just quarterly.
AI-driven PR review catches vulnerable dependencies before they ship.
Browser-based exploitation validates findings with real proof-of-concept.
Related CRITICAL CVEs from 2025
View all →Huang Yaoshi Pharmaceutical Management Software through 16.0 allows arbitrary file upload via a .asp
Unrestricted Upload of File with Dangerous Type vulnerability in themeglow JobBoard Job listing job-
An issue was discovered in Aviatrix Controller before 7.1.4191 and 7.2.x before 7.2.4996. Due to the
Unrestricted Upload of File with Dangerous Type vulnerability in jumpdemand 4ECPS Web Forms 4ecps-we
An os command injection vulnerability exists in the touchlist_sync.cgi touchlistsync() functionality
A stack-based buffer overflow vulnerability exists in the touchlist_sync.cgi touchlistsync() functio
A buffer overflow vulnerability exists in the login.cgi Goto_chidx() functionality of Wavlink AC3000
A firmware update vulnerability exists in the login.cgi functionality of Wavlink AC3000 M33A8.V5030.
A static login vulnerability exists in the wctrls functionality of Wavlink AC3000 M33A8.V5030.210505
Multiple OS command injection vulnerabilities exist in the login.cgi set_sys_init() functionality of
Multiple OS command injection vulnerabilities exist in the login.cgi set_sys_init() functionality of
Multiple OS command injection vulnerabilities exist in the login.cgi set_sys_init() functionality of