CVE-2021-1879
Apple iOS, iPadOS, and watchOS WebKit Cross-Site Scripting (XSS) Vulnerability
CVSS
6.1MediumExploit odds (EPSS)7.08%Chance of exploitation activity in the next 30 days, higher than 94% of CVEs. Scored 23 Oct 2026FIRST EPSS
CISA required actionApply updates per vendor instructions. CISA KEV
What fixes it
A fixed version on one release line is not the upgrade target for every line. Check your exact version and any vendor backports.
Timeline
Description
Apple iOS, iPadOS, and watchOS WebKit contain an unspecified vulnerability that allows for universal cross-site scripting (XSS) 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.
Text from CVE List
Affected versions 3
- iOS and iPadOSaffected: unspecified before 14.4CVE List
- iOSaffected: unspecified before 12.5CVE List
- watchOSaffected: unspecified before 7.3CVE List
References 5
- nvd.nist.gov/vuln/detail/CVE-2021-1879Referencevia CISA KEV
- support.apple.com/en-us/HT212256Referencevia CVE List
- support.apple.com/en-us/HT212257Referencevia CVE List
- support.apple.com/en-us/HT212258Referencevia CVE List
- cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-1879Referencevia CVE List