Live › vulnerability › CVE-2021-30663
Go to dashboardAn integer overflow in Apple's WebKit browser engine lets a crafted web page run code when it is processed, affecting iOS, iPadOS, macOS, tvOS and Safari. The CISA KEV catalog lists it as actively exploited in the wild.
Summary written from the sources below. Check the originals before acting.
First seen by InfraStack 2026-10-23 19:11 UTC, 3h before NVD. All times on this page are UTC.
Apply updates per vendor instructions.
| Product | Ecosystem | Affected | Fixed in |
|---|---|---|---|
| Apple Multiple Products | vendor | – | – |
Check the device OS version (iOS/iPadOS Settings > General > About, macOS About This Mac) against Apple's security notes for this CVE.
Update iOS, iPadOS, macOS, tvOS and Safari to a release that includes Apple's fix for CVE-2021-30663, as CISA directs (apply updates per vendor instructions).
Each row is the first time that source carried this signal. The analyst’s rows are its own findings.
Apple iOS, iPadOS, macOS, tvOS, and Safari WebKit contain an integer overflow vulnerability that leads to code execution 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.
CISA required action: Apply updates per vendor instructions.
This page as .md · .json · in your agent: get_signal("CVE-2021-30663")
CISA KEV catalog, Creative Commons 0 · EPSS scores by FIRST, used with attribution · NVD data is provided by NIST and is public domain. Posts quoted belong to their authors.