What is CVE-2025-6556?

CVE-2025-6556 is a medium-severity vulnerability in Google Chrome, classified under Authentication Bypass Using an Alternate Path or Channel. CVSS score: 5.4/10. Published 2025-06-24.

How severe is CVE-2025-6556?

Medium severity. CVSS v3 base score is 5.4 out of 10.

Vulnerability in Google Chrome

CVE-2025-6556

Insufficient policy enforcement in Loader in Google Chrome prior to 138.0.7204.49 allowed a remote attacker to bypass content security policy via a crafted HTML page. (Chromium security severity: Low)

EPSS: 0.002 (5.3th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 5.4 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:N.

Affected products

Google Chrome — versions 138.0.7204.49

Weakness classification (CWE)

CWE-288 — Authentication Bypass Using an Alternate Path or Channel

References

chrome-cve-admin@google.com (Vendor Advisory)
chrome-cve-admin@google.com (Permissions Required, Issue Tracking)

Frequently asked questions

What is CVE-2025-6556?: CVE-2025-6556 is a medium-severity vulnerability in Google Chrome, classified under Authentication Bypass Using an Alternate Path or Channel. CVSS score: 5.4/10. Published 2025-06-24.
How severe is CVE-2025-6556?: Medium severity. CVSS v3 base score is 5.4 out of 10.