CVE-2020-9861

CVE-2020-9861 is a high-severity vulnerability in Apple Swift with a CVSS 3.x base score of 7.5. 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-674.

Key facts

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.

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 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.
Is CVE-2020-9861 being actively exploited?
It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (70th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2020-9861?
CVE-2020-9861 affects Apple Swift. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2020-9861?
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-2020-9861 published?
CVE-2020-9861 was published on 2020-11-02 and last updated on 2026-06-17.

References

Affected products (1)

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