Is It On KEV?

Apple iOS

YES - ON THE CISA KEV LIST
CVE-2021-30666

Apple iOS WebKit Buffer Overflow Vulnerability

CISA catalog due date2021-11-17
overdue since 2021-11-17
EPSS exploit probability (next 30 days)3.0% · 87percentile
From CVE publication to KEV listing56 days (2021-09-08 → 2021-11-03)
Remediation window (KEV listing to due date)14 days
Days on the KEV list1834 days
Date added to KEV2021-11-03
Known ransomware campaign useUnknown
VendorApple
ProductiOS
Weaknesses (CWE)CWE-119

Apple: 96 entries (5.4% of all KEV entries are from this vendor); 10 added in 2026.

BOD 26-04 note: this is the date printed in the CISA catalog. A federal agency's actual deadline is set by its SSVC tier - Act (3 days), Attend (14 days), Track (60 days), or the next scheduled upgrade - counted from the KEV listing date or the date the vulnerability is identified in its environment, whichever comes first. Use the tier helper on each CVE page for your own window.

Your BOD 26-04 window (SSVC tier helper)

Your remediation window ends:

Description

Apple iOS WebKit contains a buffer-overflow vulnerability that leads to code execution when processing maliciously crafted web content. This vulnerability could impact HTML parsers that use WebKit, including but not limited to Apple Safari and non-Apple products which rely on WebKit for HTML processing.

Required action (CISA)

Apply updates per vendor instructions.

Notes

https://nvd.nist.gov/vuln/detail/CVE-2021-30666

References

Other KEV entries for this vendor: Apple

Apple - Vendors with KEV entries

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