CVE-2021-30666VulnerabilityPublished 11/03/2021Updated 10/24/2026
CVE-2021-30666: Apple iOS WebKit Buffer Overflow Vulnerability
Affects Apple iOSSource CISA KEV
Severity
HighNo CVSS score published yet
- Exploitation
Actively exploited – in CISA KEV since 11/03/2021
- KEV deadline
- 11/17/2021
- EPSS
- 3.0% chance of exploitation in 30 days – higher than 87% of CVEs
What to do
CISA required action
Apply updates per vendor instructions.
Description
CVE-2021-30666 is a buffer overflow vulnerability in Apple iOS WebKit that allows code execution when processing maliciously crafted web content. It affects HTML parsers using WebKit, including Apple Safari and other products relying on WebKit. The vulnerability has been exploited in the wild. No specific affected versions or patch information are provided.