CVE-2021-1879
Apple iOS, iPadOS, and watchOS WebKit Cross-Site Scripting (XSS) Vulnerability
IN CISA KEV
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.
- Vendor
- Apple
- Product
- iOS, iPadOS, and watchOS
- CVSS
- No score recorded (no NVD record loaded for this entry)
- CWE
- CWE-79
- Published
- Not recorded
- NVD modified
- Not recorded
CISA KEV
- Date added
- 2021-11-03
- Due date
- 2021-11-17
- Ransomware use
- Unknown
- Required action
- Apply updates per vendor instructions.
EPSS
7.08% chance of exploitation in the next 30 days (percentile 94th)
FIRST EPSS, updated 17 Oct 2026. About EPSS
CVSS is severity, EPSS is likelihood, KEV means already exploited. EPSS is a statistical probability, not a certainty: a low score does not make a bug safe, and a high one does not prove it is being exploited.
Data last updated 18 Oct 2026. Sources: NVD API 2.0, CISA KEV catalog, FIRST EPSS. Links: NVD, CISA KEV. Metadata only. ThreatWire does not host exploit code.