How severe is CVE-2020-9966?

CVE-2020-9966 has a CVSS 3.x base score of 7.8, rated high severity. It is exploitable over local access with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2020-9966 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (65th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2020-9966?

CVE-2020-9966 primarily affects Apple Ipados. In total, 5 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2020-9966?

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-2020-9966 published?

CVE-2020-9966 was published on 2020-12-08 and last updated on 2026-06-17.

CVE-2020-9966

CVE-2020-9966 is a high-severity vulnerability in Apple Ipados with a CVSS 3.x base score of 7.8. 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-125.

Key facts

Severity: High (CVSS 3.x base score 7.8)
CVSS v2: 6.8
EPSS exploit prediction: 1% (65th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-125
Affected product: Apple Ipados
Published: 2020-12-08
Last modified: 2026-06-17

Description

An out-of-bounds read was addressed with improved input validation. This issue is fixed in macOS Big Sur 11.0.1, watchOS 7.0, tvOS 14.0, iOS 14.0 and iPadOS 14.0. An application may be able to execute arbitrary code with kernel privileges.

Frequently asked questions

What is CVE-2020-9966?: An out-of-bounds read was addressed with improved input validation. This issue is fixed in macOS Big Sur 11.0.1, watchOS 7.0, tvOS 14.0, iOS 14.0 and iPadOS 14.0. An application may be able to execute arbitrary code with kernel privileges.
How severe is CVE-2020-9966?: CVE-2020-9966 has a CVSS 3.x base score of 7.8, rated high severity. It is exploitable over local access with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2020-9966 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (65th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2020-9966?: CVE-2020-9966 primarily affects Apple Ipados. In total, 5 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2020-9966?: 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-2020-9966 published?: CVE-2020-9966 was published on 2020-12-08 and last updated on 2026-06-17.

References

Affected products (5)

cpe:2.3:o:apple:ipados:*:*:*:*:*:*:*:*
cpe:2.3:o:apple:iphone_os:*:*:*:*:*:*:*:*
cpe:2.3:o:apple:mac_os_x:*:*:*:*:*:*:*:*
cpe:2.3:o:apple:tvos:*:*:*:*:*:*:*:*
cpe:2.3:o:apple:watchos:*:*:*:*:*:*:*:*

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