CVE-2026-33210
CriticalCVSS 9.1Exploitation Probability (EPSS)
Elevated risk55th percentile - higher than 55% of all known CVEs
Summary
A format string injection vulnerability in Ruby JSON (versions 2.14.0 to before 2.15.2.1, 2.17.1.2, and 2.19.2) allows denial of service or information disclosure when the allow_duplicate_key: false parsing option is used on user-supplied documents. This issue has been patched in versions 2.15.2.1, 2.17.1.2, and 2.19.2.
Risk Assessment
An attacker can cause denial of service or leak sensitive information from the system, threatening the availability and confidentiality of organizational data.
Recommendation
Immediately update the Ruby JSON library to one of the patched versions: 2.15.2.1, 2.17.1.2, or 2.19.2.
Other vulnerabilities in Ruby JSON
See all- CVE-2026-71847High
Ruby JSON versions 2.20.0 through 2.21.2 have a heap-use-after-free vulnerability in the native C extension. After consuming the input buffer of JSON::ResumableParser, state pointers remain pointing to released storage, and when partial_value reconstructs an incomplete object with duplicate keys, the duplicate-key warning path dereferences stale pointers, potentially terminating the Ruby process.
- CVE-2026-54696Low
A heap buffer overflow vulnerability in Ruby JSON versions 2.9.0 through 2.19.8 occurs when generating JSON for an oversized streamed object. An attacker can provide a controlled string near 16 KB, causing writes past the internal JSON generator buffer.
Original NVD description (English source)
Ruby JSON is a JSON implementation for Ruby. From version 2.14.0 to before versions 2.15.2.1, 2.17.1.2, and 2.19.2, a format string injection vulnerability can lead to denial of service attacks or information disclosure, when the allow_duplicate_key: false parsing option is used to parse user supplied documents. This issue has been patched in versions 2.15.2.1, 2.17.1.2, and 2.19.2.
Vulnerability data from NVD (NIST) · CISA KEV · EPSS