CVE-2020-9861

Name: CVE-2020-9861
Creator: NVD / NIST
Published: 2020-11-02T23:15:12.667+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

HIGHCVSS 7.5/10EPSS 1.43%

Last modified Jun 17, 2026

CVE-2020-9861 is a high-severity vulnerability rated 7.5/10 on the CVSS scale. A stack overflow issue existed in Swift for Linux. The issue was addressed with improved input validation for dealing with deeply nested malicious JSON input.. EPSS estimates a 1.43% chance of exploitation in the next 30 days.

Description

A stack overflow issue existed in Swift for Linux. The issue was addressed with improved input validation for dealing with deeply nested malicious JSON input.

Metrics

CVSS 3.1

7.5/10

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

EPSS Probability

1.43%

69.7th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-674

Affected Software

Vendor	Product	Versions
Apple	Swift	<= 5.1.4

References

Timeline

Published: Nov 2, 2020
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2020-9861?

A stack overflow issue existed in Swift for Linux. The issue was addressed with improved input validation for dealing with deeply nested malicious JSON input.

How severe is CVE-2020-9861?

CVE-2020-9861 has a CVSS score of 7.5/10 (HIGH severity). The EPSS model estimates a 1.43% probability of exploitation in the next 30 days.

How do I fix CVE-2020-9861?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2020-9861?

Run a free Strix scan to check your systems for this vulnerability.

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Source: NVD / NIST