CVE-2021-30533: Google Chromium PopupBlocker Security Bypass Vulnerability

Medium severity, CVSS 6.5. Actively exploited: in CISA KEV since 2022-06-27. EPSS: 16.7% chance of exploitation in the next 30 days.

Insufficient policy enforcement in PopupBlocker in Google Chrome prior to 91.0.4472.77 allowed a remote attacker to bypass navigation restrictions via a crafted iframe.

Affected products

• Fedoraproject Fedora: version 33 only; version 34 only
• Google Chrome: before 91.0.4472.77 (fixed in 91.0.4472.77)

Published 2021-06-07. Last modified 2026-06-17.