How severe is CVE-2019-8503?

CVE-2019-8503 has a CVSS 3.x base score of 8.8, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2019-8503 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (76th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2019-8503?

CVE-2019-8503 primarily affects Apple Icloud. In total, 5 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2019-8503?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

When was CVE-2019-8503 published?

CVE-2019-8503 was published on 2019-12-18 and last updated on 2026-06-17.

CVE-2019-8503

CVE-2019-8503 is a high-severity vulnerability in Apple Icloud with a CVSS 3.x base score of 8.8. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-20.

Key facts

Severity: High (CVSS 3.x base score 8.8)
CVSS v2: 9.3
EPSS exploit prediction: 2% (76th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-20
Affected product: Apple Icloud
Published: 2019-12-18
Last modified: 2026-06-17

Description

A logic issue was addressed with improved validation. This issue is fixed in iOS 12.2, tvOS 12.2, Safari 12.1, iTunes 12.9.4 for Windows, iCloud for Windows 7.11. A malicious website may be able to execute scripts in the context of another website.

Frequently asked questions

What is CVE-2019-8503?: A logic issue was addressed with improved validation. This issue is fixed in iOS 12.2, tvOS 12.2, Safari 12.1, iTunes 12.9.4 for Windows, iCloud for Windows 7.11. A malicious website may be able to execute scripts in the context of another website.
How severe is CVE-2019-8503?: CVE-2019-8503 has a CVSS 3.x base score of 8.8, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2019-8503 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (76th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2019-8503?: CVE-2019-8503 primarily affects Apple Icloud. In total, 5 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2019-8503?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
When was CVE-2019-8503 published?: CVE-2019-8503 was published on 2019-12-18 and last updated on 2026-06-17.

References

Affected products (5)

cpe:2.3:a:apple:icloud:*:*:*:*:*:windows:*:*
cpe:2.3:a:apple:itunes:*:*:*:*:*:windows:*:*
cpe:2.3:a:apple:safari:*:*:*:*:*:*:*:*
cpe:2.3:o:apple:iphone_os:*:*:*:*:*:*:*:*
cpe:2.3:o:apple:tvos:*:*:*:*:*:*:*:*

More vulnerabilities in Apple Icloud

CVE-2019-8756 — Critical (CVSS 9.8): Multiple memory corruption issues were addressed with improved input validation. This issue is fixed in macOS Catalina…
CVE-2019-8749 — Critical (CVSS 9.8): Multiple memory corruption issues were addressed with improved input validation. This issue is fixed in macOS Catalina…
CVE-2019-8746 — Critical (CVSS 9.8): An out-of-bounds read was addressed with improved input validation. This issue is fixed in macOS Catalina 10.15, iOS…
CVE-2020-9895 — Critical (CVSS 9.8): A use after free issue was addressed with improved memory management. This issue is fixed in iOS 13.6 and iPadOS 13.6,…
CVE-2020-9850 — Critical (CVSS 9.8): A logic issue was addressed with improved restrictions. This issue is fixed in iOS 13.5 and iPadOS 13.5, tvOS 13.4.5,…
CVE-2020-3911 — Critical (CVSS 9.8): A buffer overflow was addressed with improved bounds checking. This issue is fixed in iOS 13.4 and iPadOS 13.4, macOS…

All CVEs affecting Apple Icloud →

Other CWE-20 (Improper Input Validation) vulnerabilities

CVE-2026-48316 — Critical (CVSS 10.0): ColdFusion versions 2025.9, 2023.20 and earlier are affected by an Improper Input Validation vulnerability that could…
CVE-2026-48281 — Critical (CVSS 10.0): ColdFusion versions 2025.9, 2023.20 and earlier are affected by an Improper Input Validation vulnerability that could…
CVE-2026-48277 — Critical (CVSS 10.0): ColdFusion versions 2025.9, 2023.20 and earlier are affected by an Improper Input Validation vulnerability that could…
CVE-2026-48055 — Critical (CVSS 10.0): Streambert is a cross-platform Electron Desktop App to stream and download any video media. In versions 2.4.0 and…
CVE-2026-34910 — Critical (CVSS 10.0): A malicious actor with access to the network could exploit an Improper Input Validation vulnerability found in UniFi OS…
CVE-2026-33587 — Critical (CVSS 10.0): Lack of user input sanitisation in Open Notebook v1.8.3 allows the application user to execute Python code (and…

Browse all CWE-20 (Improper Input Validation) vulnerabilities →