CVE-2020-9991

This issue was addressed with improved checks. This issue is fixed in macOS Big Sur 11.0.1,...

7.5 High

This issue was addressed with improved checks. This issue is fixed in macOS Big Sur 11.0.1, watchOS 7.0, iOS 14.0 and iPadOS 14.0, iCloud for Windows 7.21, tvOS 14.0. A remote attacker may be able to cause a denial of service.

Attack profile

How easy it is to exploit

Attack vector: Network
Complexity: Low
Privileges needed: None
User interaction: None

What an attacker can affect

Confidentiality: None
Integrity: None
Availability: High

Exploit likelihood

2.82%Up 2.4 points since Apr 14, 2021

What each source reports

NVD Score used 7.5

Record: CVE-2020-9991
CVSS 3.1: 7.5 HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
CVSS 2.0: 5.0 MediumAV:N/AC:L/Au:N/C:N/I:N/A:P
Updated: 2026-11-02

CVE List No score

Record: CVE-2020-9991
Updated: 2026-11-02

EUVDEUVD-2020-30770 No score

Record: EUVD-2020-30770
Updated: 2026-11-03

GitHub AdvisoriesGHSA-5pgw-jw9q-8cfq 7.5

This issue was addressed with improved checks. This issue is fixed in macOS Big Sur 11.0.1,...

Record: GHSA-5pgw-jw9q-8cfq
CVSS 3.1: 7.5 HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Updated: 2026-11-02

OSVUBUNTU-CVE-2020-9991 7.5

Record: UBUNTU-CVE-2020-9991
CVSS 3.1: 7.5 HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Updated: 2026-11-02

Affected products

Affected packages

Affected packages
Package	Affected	Fixed
`sqlite` Ubuntu:16.04:LTS	All versions, plus listed versions 2.8.17-12fakesync1	None known

History

History
Recorded	Changed	Sources
Nov 3, 2026	aliases	EUVD
Nov 2, 2026	first indexed	CVE List, GitHub Advisories, NVD, OSV

Dates are when Every CVE recorded each change. Upstream dates may differ.

In short

CVE-2020-9991 is a high vulnerability (CVSS 7.5) in Apple Icloud, published December 8, 2020. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 2.82%, the 86th percentile. No source names a fixed version.

References

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