CVE-2021-30533 — Google Chromium PopupBlocker

Google Chromium PopupBlocker Security Bypass Vulnerability

Added to KEV

2022-06-27

Federal due date

2022-07-18

Vendor

Google

Product

Chromium PopupBlocker

EPSS

95.1th percentile (score 0.167, as of 2026-06-08)

NVD CVSS v3.1

—

Ransomware use

Unknown

Upstream

https://nvd.nist.gov/vuln/detail/CVE-2021-30533

CISA short description

Google Chromium PopupBlocker contains an insufficient policy enforcement vulnerability that allows a remote attacker to bypass navigation restrictions via a crafted iframe. This vulnerability could affect multiple web browsers that utilize Chromium, including, but not limited to, Google Chrome, Microsoft Edge, and Opera.

Required action

Apply updates per vendor instructions.

EPSS percentile is the FIRST.org exploit-probability ranking as of the date noted above; it moves daily. CVSS reflects NVD's analysis at time of publication.