What’s Vulnerable › Vulnerabilities

CVE-2021-30665: Apple Multiple Products WebKit Memory Corruption Vulnerability

• Severity: high (CVSS 8.8 v3.1)
• Exploited in the wild: yes — in CISA KEV since 2021-11-03
• EPSS: 3.7% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2021-09-08 · updated 2026-06-17
• Weakness: CWE-787

Description

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..

Affected products

• Apple iPadOS: before 14.5.1 — fixed in 14.5.1
• Apple Iphone Os: before 12.5.3; from 13.0 before 14.5.1 — fixed in 12.5.3, 14.5.1
• Apple macOS: before 11.3.1 — fixed in 11.3.1
• Apple tvOS: before 14.6 — fixed in 14.6
• Apple watchOS: before 7.4.1 — fixed in 7.4.1

How to fix

Upgrade to a fixed version: Apple iPadOS 14.5.1; Apple Iphone Os 12.5.3, 14.5.1; Apple macOS 11.3.1; Apple tvOS 14.6; Apple watchOS 7.4.1. Check the vendor advisory for mitigations.

References

• https://support.apple.com/en-us/HT212335
• https://support.apple.com/en-us/HT212336
• https://support.apple.com/en-us/HT212339
• https://support.apple.com/en-us/HT212341
• https://support.apple.com/en-us/HT212532
• https://support.apple.com/en-us/HT212335
• https://support.apple.com/en-us/HT212336
• https://support.apple.com/en-us/HT212339
• https://support.apple.com/en-us/HT212341
• https://support.apple.com/en-us/HT212532
• https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-30665

Get alerted when CVE-2021-30665 or the next vulnerability affects your stack