Improperly implemented security check for standard in Google Chromium - CVE-2025-9866

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Main Vulnerability Database Vulnerabilities #VU114893

Improperly implemented security check for standard in Google Chromium - CVE-2025-9866

Published: September 2, 2025 / Updated: September 6, 2025


Vulnerability identifier: #VU114893
CSH Severity: High
CVSS v4: 7 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:H/VI:N/VA:H/SC:N/SI:N/SA:N]
CVE-ID: CVE-2025-9866
CWE-ID: CWE-358
Exploitation vector: Remote access
Exploit availability: No public exploit available

Vulnerability details

The vulnerability allows a remote attacker to gain access to sensitive information.

The vulnerability exists due to incorrect implementation in Extensions in Google Chrome. A remote attacker can create a specially crafted web page, trick the victim into visiting it and gain access to sensitive information.


Affected software

Google Chromium
Microsoft Edge
Google Chrome
Prisma Access Browser
Debian Linux
Fedora
Chrome OS
chromium
chromium (Debian package)
cef

How to mitigate CVE-2025-9866

Install update from vendor's website.

Google Chromium - update to 140.0.7339.80
Microsoft Edge - update to 140.0.3485.54
Google Chrome - update to 140.0.7339.80
chromium - addressed in versions 140.0.7339.80-1.el9, 140.0.7339.80-1.el10_2, 140.0.7339.80-1.fc41, 140.0.7339.80-1.fc42, 140.0.7339.80-1.fc43, 140.0.7339.127-1.el9, 140.0.7339.127-1.el10_2, 140.0.7339.127-1.fc41, 140.0.7339.127-1.fc42, 140.0.7339.127-1.fc43
chromium (Debian package) - addressed in versions 140.0.7339.80-1~deb12u1, 140.0.7339.80-1~deb13u1
Chrome OS - update to 140.0.7339.201
cef - addressed in versions 140.1.15^chromium140.0.7339.207-3.fc42, 140.1.15^chromium140.0.7339.207-3.fc43
Prisma Access Browser - update to 141.6.4.55

External References

Related Security Bulletins