Apple iOS, iPadOS, and macOS WebKit Remote Code Execution Vulnerability

Added to KEV
2021-11-03
Federal due date
2021-11-17
Vendor
Apple
Product
iOS, iPadOS, and macOS
EPSS
78.9th percentile (score 0.012, as of 2026-06-08)
NVD CVSS v3.1
Ransomware use
Unknown
Upstream
https://nvd.nist.gov/vuln/detail/CVE-2021-1870

CISA short description

Apple iOS, iPadOS, and macOS WebKit contain an unspecified logic vulnerability that allows a remote attacker to execute code. 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

Apply updates per vendor instructions.

EPSS percentile is the FIRST.org exploit-probability ranking as of the date noted above; it moves daily. CVSS reflects NVD's analysis at time of publication.