Use of Externally-Controlled Format String Affecting json package, versions >=2.14.0, <2.15.2.1>=2.16.0, <2.17.1.2>=2.18.0, <2.19.2
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- published19 Mar 2026
- disclosed19 Mar 2026
- creditDavidKorczynski
Introduced: 19 Mar 2026
NewCVE-2026-33210 (opens in a new tab)Common Vulnerabilities and Exposures (CVE) are common identifiers for publicly known security vulnerabilities
Common Weakness Enumeration (CWE) is a category system for software weaknesses
How to fix?
Upgrade json to version 2.15.2.1, 2.17.1.2, 2.19.2 or higher.
Overview
json is a JSON implementation as a Ruby extension in C.
Affected versions of this package are vulnerable to Use of Externally-Controlled Format String in JSON.parse(doc, allow_duplicate_key: false). An attacker can cause denial of service or disclose sensitive information via malicious format strings. This is only exploitable if the allow_duplicate_key: false option is explicitly enabled.