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.
Affected products
ruby-lang: json
References7
- github.com/ruby/json/security/advisories/GHSA-3m6g-2423-7cp3 MitigationVendor Advisory
- access.redhat.com/errata/RHSA-2026:20596
- access.redhat.com/errata/RHSA-2026:20606
- access.redhat.com/errata/RHSA-2026:57565
- access.redhat.com/security/cve/CVE-2026-33210
- bugzilla.redhat.com/show_bug.cgi?id=2449871
- security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-33210…
Metrics
- CVSS 3.1
-
9.1
CRITICAL
Score source: NVD
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H - CVSS 4.0
-
8.3
HIGH
Score source: CNA
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X - EPSS — exploit probability
- 1% percentile: 60 · as of 12 November 2026
- CWE
- CWE-134
Could this be exploited in your environment?
A patch closes the known hole. A penetration test shows what an attacker can still reach — with proof.