What’s Vulnerable › Vulnerabilities

CVE-2021-1826

• Severity: medium (CVSS 6.1 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 1.1% 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-79

Description

A logic issue was addressed with improved restrictions. This issue is fixed in macOS Big Sur 11.3, iOS 14.5 and iPadOS 14.5, watchOS 7.4, tvOS 14.5. Processing maliciously crafted web content may lead to universal cross site scripting.

Affected products

• Apple iPadOS: before 14.5 — fixed in 14.5
• Apple Iphone Os: before 14.5 — fixed in 14.5
• Apple macOS: from 11.0 before 11.3 — fixed in 11.3
• Apple tvOS: before 14.5 — fixed in 14.5
• Apple watchOS: before 7.4 — fixed in 7.4

How to fix

Upgrade to a fixed version: Apple iPadOS 14.5; Apple Iphone Os 14.5; Apple macOS 11.3; Apple tvOS 14.5; Apple watchOS 7.4. Check the vendor advisory for mitigations.

References

• https://support.apple.com/en-us/HT212317
• https://support.apple.com/en-us/HT212323
• https://support.apple.com/en-us/HT212324
• https://support.apple.com/en-us/HT212325
• https://support.apple.com/en-us/HT212317
• https://support.apple.com/en-us/HT212323
• https://support.apple.com/en-us/HT212324
• https://support.apple.com/en-us/HT212325

Get alerted when CVE-2021-1826 or the next vulnerability affects your stack