No exploitation reportedFix available

CVE-2020-3910

Q: Is CVE-2020-3910 actively exploited?

Active exploitation of CVE-2020-3910 has not been confirmed. Its EPSS score was 1.6% on 2026-10-22, the estimated probability of exploitation in the next 30 days.

Q: What is the CVSS score for CVE-2020-3910?

CVE-2020-3910 has a CVSS v3 base score of 9.8 (CRITICAL severity), with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

No exploitation reported by the sources we read.

Published2020-04-01
Fixed in10.9.3
WeaknessCWE-120

Am I affected?

With a domain, we read the version its public headers and pages expose. A distribution build can carry the fix under an older number.

Description

A buffer overflow was addressed with improved size validation. This issue is fixed in iOS 13.4 and iPadOS 13.4, macOS Catalina 10.15.4, tvOS 13.4, watchOS 6.2, iTunes for Windows 12.10.5, iCloud for Windows 10.9.3, iCloud for Windows 7.18. Multiple issues in libxml2.

Timeline

dates in UTC

2020-04-0118:15CVE publishedNVD

Observed activity

isMalicious corpus · updated 2026-10-23 18:48 UTC

Indicators tagged with this CVE, per day0 indicators over 7 days

Block these indicators

Firewall list (EDL, text): https://api.ismalicious.com/edl/cve/CVE-2020-3910?format=txt
CSV export: https://api.ismalicious.com/edl/cve/CVE-2020-3910?format=csv
TAXII collection of exploited CVEs
The EDL and CSV take an API key on the Pro plan.

Versions per branch

NVD

Apple icloud

Branch	Affected	Fixed in	Source
10.9	< 10.9.3	10.9.3	NVD

Apple ipados

Branch	Affected	Fixed in	Source
13.4	< 13.4	13.4	NVD

Apple iphone os

Branch	Affected	Fixed in	Source
13.4	< 13.4	13.4	NVD

4 more products in the sources.

as publishedRanges as NVD and OSV publish them; a distribution’s build can be fixed under an older number.

Fix

Update Apple icloud to 10.9.3

Advisories and patches

support.apple.comVendor Advisory
support.apple.comVendor Advisory
support.apple.comVendor Advisory
support.apple.comVendor Advisory
support.apple.comVendor Advisory
support.apple.comVendor Advisory

Detection

Nuclei template: none so far
Exploit-DB: no entry
Proof-of-concept repositories: none listed

Sources

NVDCVSS 3.19.8read 2026-10-23
NVDCVSS 2.07.5read 2026-10-23
NVDweakness (CWE)CWE-120read 2026-10-23
FIRST EPSSEPSS score1.6 %2026-10-22

Technical details

CVSS v3 Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Published: 2020-04-01
Last Modified: 2026-06-17
NVD status: Modified

Frequently asked questions

What is CVE-2020-3910?

Is CVE-2020-3910 actively exploited?

Active exploitation of CVE-2020-3910 has not been confirmed. Its EPSS score was 1.6% on 2026-10-22, the estimated probability of exploitation in the next 30 days.

What is the CVSS score for CVE-2020-3910?

CVE-2020-3910 has a CVSS v3 base score of 9.8 (CRITICAL severity), with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

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