What is CVE-2018-4436?

CVE-2018-4436 is a high-severity vulnerability in Apple Iphone OS, classified under Improper Certificate Validation. CVSS score: 7.5/10. Published 2019-04-03.

How severe is CVE-2018-4436?

High severity. CVSS v3 base score is 7.5 out of 10.

Vulnerability in Apple Iphone OS

CVE-2018-4436

A certificate validation issue existed in configuration profiles. This was addressed with additional checks. This issue affected versions prior to iOS 12.1.1, tvOS 12.1.1, watchOS 5.1.2.

Vulnerability class: Improper Certificate Validation

Published 2019-04-03 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 7.5 (High). Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N.

EPSS exploit prediction

EPSS: 0.009 (58.5th percentile), scored 2026-10-02.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 58th percentile — 58.5% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.009 · newest: 0.009 · change: 0.000

Affected products

Apple Iphone OS
Apple tvOS
Apple watchOS
iOS, tvOS, watchOS — versions Versions prior to: iOS 12.1.1, tvOS 12.1.1, watchOS 5.1.2

Weakness classification (CWE)

CWE-295 — Improper Certificate Validation

References

support.apple.com/kb/HT209343 (Vendor Advisory)
support.apple.com/kb/HT209342 (Vendor Advisory)
support.apple.com/kb/HT209340 (Vendor Advisory)

Frequently asked questions

What is CVE-2018-4436?: CVE-2018-4436 is a high-severity vulnerability in Apple Iphone OS, classified under Improper Certificate Validation. CVSS score: 7.5/10. Published 2019-04-03.
How severe is CVE-2018-4436?: High severity. CVSS v3 base score is 7.5 out of 10.