High 8.8Known exploited (CISA KEV)Published Apr 2, 2021

CVE-2021-1789A type confusion issue was addressed with improved state handling.

Updated under an hour ago (Oct 26, 2026, 7:23 PM ET)

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It affects Apple iOS and iPadOS and 8 other products. Add what you run to find out whether that includes you.

CISA lists it as known exploited since May 4, 2022; federal agencies had to remediate by May 25, 2022. Treat that date as your deadline.

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Exploited in the last 30 days

A type confusion issue was addressed with improved state handling. This issue is fixed in macOS Big Sur 11.2, Security Update 2021-001 Catalina, Security Update 2021-001 Mojave, tvOS 14.4, watchOS 7.3, iOS 14.4 and iPadOS 14.4, Safari 14.0.3. Processing maliciously crafted web content may lead to arbitrary code execution.

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-843
Known exploited: Added to CISA KEV May 4, 2022; federal remediation due May 25, 2022Apply updates per vendor instructions.
EPSS (exploitation in the next 30 days): 13.98% (percentile 97)
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 iOS and iPadOS apple:ios_and_ipados (from the name)	from unspecified before 14.4	CNA record
Apple macOS apple:macos (from the name)	from unspecified before 11.2	CNA record
apple ipados apple:ipados	before 14.4	NVD
apple iphone_os apple:iphone_os	before 14.4	NVD
apple mac_os_x apple:mac_os_x	from 10.14 before 10.14.6; from 10.15 before 10.15.7; 10.14.6; 10.14.6; 10.14.6; 10.14.6; 10.14.6; 10.14.6; and 10 more ranges	NVD
apple macos apple:macos	from 11.0 before 11.2	NVD
apple tvos apple:tvos	before 14.4	NVD
apple watchos apple:watchos	before 7.3	NVD
fedoraproject fedora fedoraproject:fedora	32; 33	NVD
webkitgtk webkitgtk webkitgtk:webkitgtk	before 2.30.6	NVD

References

References

https://support.apple.com/en-us/HT212147	x-refsource-misc, release-notes, vendor-advisory
https://support.apple.com/en-us/HT212146	x-refsource-misc, release-notes, vendor-advisory
https://support.apple.com/en-us/HT212148	x-refsource-misc, release-notes, vendor-advisory
https://support.apple.com/en-us/HT212149	x-refsource-misc, release-notes, vendor-advisory
https://support.apple.com/en-us/HT212152	x-refsource-misc, release-notes, vendor-advisory
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/L3L6ZZOU5JS7E3RFYGLP7UFLXCG7TNLU/	vendor-advisory, x-refsource-fedora, broken-link, mailing-list
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/JN6ZOD62CTO54CHTMJTHVEF6R2Y532TJ/	vendor-advisory, x-refsource-fedora, broken-link, mailing-list
https://security.gentoo.org/glsa/202104-03	vendor-advisory, x-refsource-gentoo, third-party-advisory
https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-1789	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.