Medium 6.5Known exploited (CISA KEV)Published Jun 7, 2021

CVE-2021-30533Insufficient 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.

Updated under an hour ago (Oct 28, 2026, 6:23 AM ET)

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It affects Google Chrome and 1 other product. Add what you run to find out whether that includes you.

CISA lists it as known exploited since Jun 27, 2022; federal agencies had to remediate by Jul 18, 2022. Treat that date as your deadline.

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Exploited in the last 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.

CVSS: 6.5 MEDIUM (v3.1, CISA ADP)CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:N
Weakness (CWE): CWE-863
Known exploited: Added to CISA KEV Jun 27, 2022; federal remediation due Jul 18, 2022Apply updates per vendor instructions.
EPSS (exploitation in the next 30 days): 16.74% (percentile 97)
Assigned by: Chrome
NVD analysis: Analyzed
Record last updated: Oct 21, 2025
First seen by InfoSec Signals: Oct 9, 2026

Affected products

Affected products

Google Chrome google:chrome (from the name)	from unspecified before 91.0.4472.77	CNA record
google chrome google:chrome	before 91.0.4472.77	NVD
fedoraproject fedora fedoraproject:fedora	33; 34	NVD

References

References

https://chromereleases.googleblog.com/2021/05/stable-channel-update-for-desktop_25.html	x-refsource-misc, release-notes, vendor-advisory
https://crbug.com/1145553	x-refsource-misc, exploit, issue-tracking, patch, vendor-advisory
https://security.gentoo.org/glsa/202107-06	vendor-advisory, x-refsource-gentoo, third-party-advisory
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/PAT6EOXVQFE6JFMFQF4IKAOUQSHMHL54/	vendor-advisory, x-refsource-fedora, mailing-list, release-notes
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/ETMZL6IHCTCTREEL434BQ4THQ7EOHJ43/	vendor-advisory, x-refsource-fedora, mailing-list, release-notes
https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-30533	us-government-resource

The CVE record on cve.org NVD's entry

The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.