How severe is CVE-2021-30611?

CVE-2021-30611 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-2021-30611 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 3% (85th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-30611?

CVE-2021-30611 primarily affects Microsoft Edge. In total, 3 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2021-30611?

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-2021-30611 published?

CVE-2021-30611 was published on 2021-09-03 and last updated on 2026-06-17.

CVE-2021-30611

CVE-2021-30611 is a high-severity vulnerability in Microsoft Edge with a CVSS 3.x base score of 8.8. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-416.

Key facts

Severity: High (CVSS 3.x base score 8.8)
CVSS v2: 6.8
EPSS exploit prediction: 3% (85th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-416
Affected product: Microsoft Edge
Published: 2021-09-03
Last modified: 2026-06-17

Description

Chromium: CVE-2021-30611 Use after free in WebRTC

Frequently asked questions

What is CVE-2021-30611?: Chromium: CVE-2021-30611 Use after free in WebRTC
How severe is CVE-2021-30611?: CVE-2021-30611 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-2021-30611 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 3% (85th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-30611?: CVE-2021-30611 primarily affects Microsoft Edge. In total, 3 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2021-30611?: 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-2021-30611 published?: CVE-2021-30611 was published on 2021-09-03 and last updated on 2026-06-17.

References

Affected products (3)

cpe:2.3:o:fedoraproject:fedora:35:*:*:*:*:*:*:*
cpe:2.3:a:microsoft:edge:*:*:*:*:*:*:*:*
cpe:2.3:a:microsoft:edge_chromium:*:*:*:*:*:*:*:*

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