How severe is CVE-2020-3847?

CVE-2020-3847 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2020-3847 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (80th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2020-3847?

CVE-2020-3847 affects Apple Mac Os X. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2020-3847?

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

When was CVE-2020-3847 published?

CVE-2020-3847 was published on 2020-04-01 and last updated on 2026-06-17.

CVE-2020-3847

CVE-2020-3847 is a critical-severity vulnerability in Apple Mac Os X with a CVSS 3.x base score of 9.8. 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: Critical (CVSS 3.x base score 9.8)
CVSS v2: 10.0
EPSS exploit prediction: 2% (80th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-20
Affected product: Apple Mac Os X
Published: 2020-04-01
Last modified: 2026-06-17

Description

An out-of-bounds read was addressed with improved input validation. This issue is fixed in macOS Catalina 10.15.3. A remote attacker may be able to leak memory.

Frequently asked questions

What is CVE-2020-3847?: An out-of-bounds read was addressed with improved input validation. This issue is fixed in macOS Catalina 10.15.3. A remote attacker may be able to leak memory.
How severe is CVE-2020-3847?: CVE-2020-3847 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2020-3847 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (80th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2020-3847?: CVE-2020-3847 affects Apple Mac Os X. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2020-3847?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.
When was CVE-2020-3847 published?: CVE-2020-3847 was published on 2020-04-01 and last updated on 2026-06-17.

References

https://support.apple.com/HT210919

Affected products (1)

cpe:2.3:o:apple:mac_os_x:*:*:*:*:*:*:*:*

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