How severe is CVE-2021-30558?

CVE-2021-30558 has a CVSS 3.x base score of 8.8, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2021-30558 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 11% (96th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-30558?

CVE-2021-30558 affects Google Chrome. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2021-30558?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

When was CVE-2021-30558 published?

CVE-2021-30558 was published on 2023-01-02 and last updated on 2026-06-17.

CVE-2021-30558

CVE-2021-30558 is a high-severity vulnerability in Google Chrome with a CVSS 3.x base score of 8.8. Its EPSS exploit-prediction score of 11% places it in the 96th percentile, indicating an elevated likelihood of exploitation.

Key facts

Severity: High (CVSS 3.x base score 8.8)
EPSS exploit prediction: 11% (96th percentile)
Actively exploited: Not listed in CISA KEV
Affected product: Google Chrome
Published: 2023-01-02
Last modified: 2026-06-17

Description

Insufficient policy enforcement in content security policy in Google Chrome prior to 91.0.4472.77 allowed a remote attacker to bypass content security policy via a crafted HTML page. (Chrome security severity: Medium)

Frequently asked questions

What is CVE-2021-30558?: Insufficient policy enforcement in content security policy in Google Chrome prior to 91.0.4472.77 allowed a remote attacker to bypass content security policy via a crafted HTML page. (Chrome security severity: Medium)
How severe is CVE-2021-30558?: CVE-2021-30558 has a CVSS 3.x base score of 8.8, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2021-30558 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 11% (96th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-30558?: CVE-2021-30558 affects Google Chrome. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2021-30558?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
When was CVE-2021-30558 published?: CVE-2021-30558 was published on 2023-01-02 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:google:chrome:*:*:*:*:*:*:*:*

More vulnerabilities in Google Chrome

CVE-2026-13782 — Critical (CVSS 10.0): Use after free in Browser in Google Chrome prior to 150.0.7871.47 allowed a remote attacker who had compromised the…
CVE-2015-8548 — Critical (CVSS 10.0): Multiple unspecified vulnerabilities in Google V8 before 4.7.80.23, as used in Google Chrome before 47.0.2526.80, allow…
CVE-2015-6791 — Critical (CVSS 10.0): Multiple unspecified vulnerabilities in Google Chrome before 47.0.2526.80 allow attackers to cause a denial of service…
CVE-2015-6788 — Critical (CVSS 10.0): The ObjectBackedNativeHandler class in extensions/renderer/object_backed_native_handler.cc in the extensions subsystem…
CVE-2015-8480 — Critical (CVSS 10.0): The VideoFramePool::PoolImpl::CreateFrame function in media/base/video_frame_pool.cc in Google Chrome before…
CVE-2015-6787 — Critical (CVSS 10.0): Multiple unspecified vulnerabilities in Google Chrome before 47.0.2526.73 allow attackers to cause a denial of service…

All CVEs affecting Google Chrome →