CVE-2020-9861 json
A stack overflow issue existed in Swift for Linux.
published 2020-11-02 6 y ago modified 2026-06-17 4 mo ago also EUVD-2020-30640
- cvss
- 7.5
- version 3.1, NVD
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 1.5%
- EPSS 1.5% chance of exploitation in 30 days, percentile 73%
- public exploits
- 0
- none known
Summary
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.
Patch / fix
- Swift Swift 5.1.5 for Linux Swift 5.1.5 for Linux
Vendor advisories
What the vendors themselves say about their products: affected, fixed or not affected, and what to do.
red hat product security vex CVE-2020-9861 updated cvss 7.5
swift: stack overflow issue via nested malicious JSON input
-
Red Hat JBoss Fuse 6 swiftnot affected: vulnerable code not present
Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf
Exploit prediction
1.45% chance of exploitation in the next 30 days, higher than 73% of all scored CVEs (FIRST EPSS, 2026-11-08).
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| NVD | 3.1 | 7.5 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H |
| NVD | 2.0 | 5.0 | AV:N/AC:L/Au:N/C:N/I:N/A:P |
Affected products
- Swift Swift 5.1.5 for Linux
Classification
- Weakness
-
- CWE-674 Uncontrolled Recursion
References
Sources
- CVE List CVE-2020-9861
- NVD CVE-2020-9861
Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.