How severe is CVE-2021-30533?

CVE-2021-30533 has a CVSS 3.x base score of 6.5, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is none, integrity high, and availability none.

Is CVE-2021-30533 being actively exploited?

Yes. CVE-2021-30533 is on CISA's Known Exploited Vulnerabilities (KEV) catalog, added on 2022-06-27, which means active exploitation has been confirmed. It should be prioritised for remediation.

What products are affected by CVE-2021-30533?

CVE-2021-30533 primarily affects Google Chrome. In total, 3 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2021-30533?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Because this CVE is known to be actively exploited, treat remediation as urgent — CISA KEV typically sets a short remediation deadline.

Does CVE-2021-30533 have an EU (EUVD) identifier?

Yes. CVE-2021-30533 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2021-17454. It is also flagged as exploited in the EUVD (since 2022-06-27).

When was CVE-2021-30533 published?

CVE-2021-30533 was published on 2021-06-07 and last updated on 2026-06-17.

CVE-2021-30533

CVE-2021-30533 is a medium-severity vulnerability in Google Chrome with a CVSS 3.x base score of 6.5. It is listed in CISA's Known Exploited Vulnerabilities (KEV) catalog, confirming it has been exploited in the wild (added 2022-06-27). The underlying weakness is classified as CWE-863.

Key facts

Severity: Medium (CVSS 3.x base score 6.5)
CVSS v2: 4.3
EPSS exploit prediction: 17% (97th percentile)
Actively exploited: Yes — listed in CISA KEV (added 2022-06-27)
EU (EUVD) id: EUVD-2021-17454
EU exploitation: Flagged exploited in the ENISA EU Vulnerability Database (since 2022-06-27)
Weakness: CWE-863
Affected product: Google Chrome
Published: 2021-06-07
Last modified: 2026-06-17

Description

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.

Frequently asked questions

What is CVE-2021-30533?: 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.
How severe is CVE-2021-30533?: CVE-2021-30533 has a CVSS 3.x base score of 6.5, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is none, integrity high, and availability none.
Is CVE-2021-30533 being actively exploited?: Yes. CVE-2021-30533 is on CISA's Known Exploited Vulnerabilities (KEV) catalog, added on 2022-06-27, which means active exploitation has been confirmed. It should be prioritised for remediation.
What products are affected by CVE-2021-30533?: CVE-2021-30533 primarily affects Google Chrome. In total, 3 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2021-30533?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Because this CVE is known to be actively exploited, treat remediation as urgent — CISA KEV typically sets a short remediation deadline.
Does CVE-2021-30533 have an EU (EUVD) identifier?: Yes. CVE-2021-30533 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2021-17454. It is also flagged as exploited in the EUVD (since 2022-06-27).
When was CVE-2021-30533 published?: CVE-2021-30533 was published on 2021-06-07 and last updated on 2026-06-17.

References

Affected products (3)

cpe:2.3:a:google:chrome:*:*:*:*:*:*:*:*
cpe:2.3:o:fedoraproject:fedora:33:*:*:*:*:*:*:*
cpe:2.3:o:fedoraproject:fedora:34:*:*:*:*:*:*:*

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