What is CVE-2019-8658?

CVE-2019-8658 is a medium-severity vulnerability in Apple Icloud, classified under Cross-site Scripting. CVSS score: 6.1/10. Published 2019-12-18.

How severe is CVE-2019-8658?

Medium severity. CVSS v3 base score is 6.1 out of 10.

Is CVE-2019-8658 known to be exploited?

1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.

XSS in Apple Icloud

CVE-2019-8658

A logic issue was addressed with improved state management. This issue is fixed in iOS 12.4, macOS Mojave 10.14.6, tvOS 12.4, watchOS 5.3, Safari 12.1.2, iTunes for Windows 12.9.6, iCloud for Windows 7.13, iCloud for Windows 10.6. Processing maliciously crafted web content may lead to universal cross site scripting.

Vulnerability class: XSS (Cross-Site Scripting)

Published 2019-12-18 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 6.1 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N.

EPSS exploit prediction

EPSS: 0.012 (68.1th percentile), scored 2026-10-02.

Low probability of exploitation in the next 30 days, but still tracked. 68th percentile — 68.1% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.012 · newest: 0.012 · change: 0.000

Affected products

Apple Icloud
Apple Icloud For Windows — versions unspecified
Apple Icloud For Windows (Microsoft Store) — versions unspecified
Apple iOS — versions unspecified
Apple Iphone OS
Apple Itunes
Apple Itunes For Windows — versions unspecified
Apple macOS — versions unspecified
Apple Mac OS X
Apple Safari — versions unspecified

Weakness classification (CWE)

CWE-79 — Cross-site Scripting

Public proof-of-concept exploits

alphaSeclab/sec-daily-2019

References

support.apple.com/HT210353 (Vendor Advisory)
support.apple.com/HT210346 (Vendor Advisory)
support.apple.com/HT210348 (Vendor Advisory)
support.apple.com/HT210351 (Vendor Advisory)
support.apple.com/HT210355 (Vendor Advisory)
support.apple.com/HT210356 (Vendor Advisory)
support.apple.com/HT210357 (Vendor Advisory)
support.apple.com/HT210358 (Vendor Advisory)

Frequently asked questions

What is CVE-2019-8658?: CVE-2019-8658 is a medium-severity vulnerability in Apple Icloud, classified under Cross-site Scripting. CVSS score: 6.1/10. Published 2019-12-18.
How severe is CVE-2019-8658?: Medium severity. CVSS v3 base score is 6.1 out of 10.
Is CVE-2019-8658 known to be exploited?: 1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.