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CVE-2021-1879: Apple iOS, iPadOS, and watchOS WebKit Cross-Site Scripting (XSS) Vulnerability
Apple iOS, iPadOS, and watchOS · in CISA KEV since 2021-11-03
2021-11-03added to KEV
2021-11-17federal remediation due date
7.08%EPSS exploit probability (30 days) 93.9th percentile
6.1 MEDIUMCVSS 3.1
Unknownknown ransomware use
215days from NVD publication to KEV
What it is
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.
Required action (CISA)
Apply updates per vendor instructions.
| CWE | CWE-79 |
|---|---|
| CVSS vector | CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N |
| NVD published | 2021-04-02 (Analyzed) |
Original records: NVD · CISA KEV · JSON: /api/cve/CVE-2021-1879.json · all KEV CVEs
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Get the full file: Exploited Vulnerabilities Brief – September 2026 ($29): this month's KEV additions ranked by EPSS, ransomware use and due date, ready to hand to a patch team. Checkout by Polar.