CVE-2026-33210

CRITICAL

Ruby JSON allow_duplicate_key - Format String Injection

Title source: manual
STIX 2.1

Description

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.

References (1)

Core 1
Core References

Scores

CVSS v3 9.1
EPSS 0.0055
EPSS Percentile 41.3%
Attack Vector NETWORK
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H

CISA SSVC

Vulnrichment
Exploitation none
Automatable no
Technical Impact partial

Details

CWE
CWE-134
Status published
Products (5)
ruby/json >= 2.14.0, < 2.15.2.1
ruby/json >= 2.16.0, < 2.17.1.2
ruby/json >= 2.18.0, < 2.19.2
ruby-lang/json 2.14.0 - 2.15.2.1
rubygems/json 2.18.0 - 2.19.2RubyGems
Published Mar 20, 2026
Tracked Since Mar 21, 2026