Vulnerability · Published Sep 3, 2025 · Assigned by Chrome
CVE-2025-9866
High 8.8
In plain English
A high-severity security flaw in Chrome from Google. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.5% (higher than 43% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Severity (CVSS 3.1)8.8High
Exploit odds (30 days)0.5%top 56.8% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack toolingNoneno public tooling known
Official description
Inappropriate implementation in Extensions in Google Chrome prior to 140.0.7339.80 allowed a remote attacker to bypass content security policy via a crafted HTML page. (Chromium security severity: Medium)
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Alpine:v3.22 | qt6-qtwebengine | 6.8.3-r1 | ALPINE-CVE-2025-9866 |
| Alpine:v3.23 | qt6-qtwebengine | 6.9.2-r1 | ALPINE-CVE-2025-9866 |
| Alpine:v3.24 | qt6-qtwebengine | 6.9.2-r1 | ALPINE-CVE-2025-9866 |
| Debian:12 | chromium | 140.0.7339.80-1~deb12u1 | DSA-5993-1 |
| Debian:12 | chromium | 140.0.7339.80-1~deb12u1 | DEBIAN-CVE-2025-9866 |
| Debian:13 | chromium | 140.0.7339.80-1~deb13u1 | DSA-5993-1 |
| Debian:13 | chromium | 140.0.7339.80-1~deb13u1 | DEBIAN-CVE-2025-9866 |
| Debian:14 | chromium | 140.0.7339.80-1 | DEBIAN-CVE-2025-9866 |
Affected products (as reported)
Weakness: CWE-693 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H