Apple iOS, iPadOS, and macOS WebKit Remote Code Execution Vulnerability
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.
- Vendor
- Apple
- Product
- iOS, iPadOS, and macOS
- CVSS
- 9.8
- EPSS (exploit probability)
- 7.7%
- Status
- kev
- CISA patch-by (BOD 22-01)
- Added to KEV
Is CVE-2021-1870 being exploited?
Yes. CISA added CVE-2021-1870 to its Known Exploited Vulnerabilities catalog on . CISA only lists a CVE when it has reliable evidence of exploitation in the wild.
FIRST's EPSS model puts the probability of exploitation activity in the next 30 days at 7.7% (scored October 14, 2026).
- CISA KEV[ LISTED ]
- ENISA EUVD (exploited)[ — ]
- CIRCL KEV[ — ]
Catalog snapshot 2026-10-21. Full cross-catalog view: /kev-comparison
What to do
CISA required actionApply updates per vendor instructions.
US federal civilian agencies must remediate by (14 days after listing) under BOD 22-01. Everyone else: that deadline is a sensible upper bound, not a target. Vendor guidance and the NVD record are linked under Source above.
Other Apple iOS, iPadOS, and macOS CVEs we track
| CVE / Vulnerability | Severity | CVSS | EPSS | Added to KEV |
|---|---|---|---|---|
| CVE-2025-43300 Apple iOS, iPadOS, and macOS Out-of-Bounds Write Vulnerability | [ CRITICAL ] | 10.0 | 32.0% | |
| CVE-2023-41064 Apple iOS, iPadOS, and macOS ImageIO Buffer Overflow Vulnerability | [ HIGH ] | 7.8 | 53.4% | |
| CVE-2023-28206 Apple iOS, iPadOS, and macOS IOSurfaceAccelerator Out-of-Bounds Write Vulnerability | [ HIGH ] | 8.6 | 23.2% | |
| CVE-2021-30900 Apple iOS, iPadOS, and macOS Out-of-Bounds Write Vulnerability | [ HIGH ] | 7.8 | 5.2% | |
| CVE-2022-32917 Apple iOS, iPadOS, and macOS Remote Code Execution Vulnerability | [ HIGH ] | 7.8 | 5.6% | |
| CVE-2020-9934 Apple iOS, iPadOS, and macOS Input Validation Vulnerability | [ MEDIUM ] | 5.5 | 3.2% | |
| CVE-2022-22620 Apple iOS, iPadOS, and macOS Webkit Use-After-Free Vulnerability | [ HIGH ] | 8.8 | 16.3% | |
| CVE-2021-30869 Apple iOS, iPadOS, and macOS Type Confusion Vulnerability | [ HIGH ] | 7.8 | 4.1% |