High 8.8Known exploited (CISA KEV)Published Sep 8, 2021

CVE-2021-30665A memory corruption issue was addressed with improved state management.

Updated under an hour ago (2026-10-19 07:10 UTC)

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It affects Apple macOS and 4 other products. Add what you run to find out whether that includes you.

CISA lists it as known exploited since Nov 3, 2021; federal agencies had to remediate by Nov 17, 2021. Treat that date as your deadline.

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Exploited in the last 30 days

A memory corruption issue was addressed with improved state management. This issue is fixed in watchOS 7.4.1, iOS 14.5.1 and iPadOS 14.5.1, tvOS 14.6, iOS 12.5.3, macOS Big Sur 11.3.1. 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..

CVSS: 8.8 HIGH (v3.1, CISA ADP)CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
Weakness (CWE): CWE-787
Known exploited: Added to CISA KEV Nov 3, 2021; federal remediation due Nov 17, 2021Apply updates per vendor instructions.
EPSS (exploitation in the next 30 days): 3.71% (percentile 90)
Assigned by: apple
NVD analysis: Analyzed
Record last updated: Oct 21, 2025
First seen by InfoSec Signals: Oct 9, 2026

Affected products

Affected products

Apple macOS apple:macos (from the name)	from unspecified before 11.3	CNA record
apple ipados apple:ipados	before 14.5.1	NVD
apple iphone_os apple:iphone_os	before 12.5.3; from 13.0 before 14.5.1	NVD
apple macos apple:macos	before 11.3.1	NVD
apple tvos apple:tvos	before 14.6	NVD
apple watchos apple:watchos	before 7.4.1	NVD

References

https://support.apple.com/en-us/HT212532x-refsource-misc, release-notes, vendor-advisory
https://support.apple.com/en-us/HT212341x-refsource-misc, release-notes, vendor-advisory
https://support.apple.com/en-us/HT212335x-refsource-misc, release-notes, vendor-advisory
https://support.apple.com/en-us/HT212336x-refsource-misc, release-notes, vendor-advisory
https://support.apple.com/en-us/HT212339x-refsource-misc, release-notes, vendor-advisory
https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-30665third-party-advisory, us-government-resource

The CVE record on cve.org NVD's entry

The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.