CVE-2026-33210
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…
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (0.86%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
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.
- CVSS 4.0
- 8.3 HIGHCVSS: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/M
- EPSS
- 0.86% probability · 56th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-134
- Affected
- ruby-lang/json
- Source
- security-advisories@github.com
References
- https://github.com/ruby/json/security/advisories/GHSA-3m6g-2423-7cp3Mitigation, Vendor Advisory
- https://access.redhat.com/errata/RHSA-2026:20596
- https://access.redhat.com/errata/RHSA-2026:20606
- https://access.redhat.com/errata/RHSA-2026:57565
- https://access.redhat.com/security/cve/CVE-2026-33210
- https://bugzilla.redhat.com/show_bug.cgi?id=2449871
- https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-33210.json
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.