Is CVE-2021-30661 being actively exploited?

Yes. CVE-2021-30661 is listed in the CISA Known Exploited Vulnerabilities (KEV) catalog, added on November 3, 2021.

What is the CVSS score for CVE-2021-30661?

CVE-2021-30661 has a CVSS 3.1 base score of 8.8 (HIGH).

CVE-2021-30661

HIGH · CVSS 8.8CISA KEV: actively exploitedEPSS 4.5%EU EUVD: exploited

A use after free issue was addressed with improved memory management. This issue is fixed in Safari 14.1, iOS 12.5.3, iOS 14.5 and iPadOS 14.5, watchOS 7.4, tvOS 14.5, macOS Big Sur 11.3. Processing maliciously crafted web content may lead to arbitrary code execution. Apple is aware of a report that this issue may have been actively exploited..

Key facts

CVSS score: 8.8 (v3.1)
Severity: HIGH
CVSS vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
Weakness (CWE): CWE-416
EPSS score: 4.5% (91th percentile)
In CISA KEV: Yes, added November 3, 2021
In EU EUVD: Yes (EUVD-2021-17578)
Published: September 8, 2021
NVD last modified: June 17, 2026
Status: Analyzed

CISA Known Exploited Vulnerability

Apple Multiple Products WebKit Storage Use-After-Free Vulnerability

Added to the KEV catalog on November 3, 2021; federal remediation due November 17, 2021.

EU Vulnerability Database (EUVD)

This vulnerability is also tracked by ENISA as EUVD-2021-17578 in the EU Vulnerability Database. ENISA flags it as known exploited. Last updated in EUVD on October 21, 2025.

View on the EU Vulnerability Database

Affected products

apple / ipados
apple / iphone os
apple / macos
apple / safari
apple / tvos
apple / watchos

Certified products that may be affected

1 FIPS 140 or Common Criteria certified product, from automated matching by sec-certs.org.

Apple macOS 11 Big Sur: Contacts - Apple Inc. - Common Criteria CCEVS-VR-VID-11243-2022 - archived

References

https://support.apple.com/en-us/HT212317(Vendor Advisory)
https://support.apple.com/en-us/HT212318(Vendor Advisory)
https://support.apple.com/en-us/HT212323(Vendor Advisory)
https://support.apple.com/en-us/HT212324(Vendor Advisory)
https://support.apple.com/en-us/HT212325(Vendor Advisory)
https://support.apple.com/en-us/HT212341(Vendor Advisory)
https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-30661(Third Party Advisory, US Government Resource)

Last updated September 17, 2026 · Source: NVD, CISA KEV, FIRST.org EPSS

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