{"id":"CVE-2026-33210","aliases":["GHSA-3m6g-2423-7cp3"],"url":"https://o3.security/vulnerability/CVE-2026-33210","summary":"Ruby JSON has a format string injection vulnerability","details":"### Impact\n\nA format string injection vulnerability than that lead to denial of service attacks or information disclosure, when the `allow_duplicate_key: false` parsing option is used to parse user supplied documents. \n\nThis option isn't the default, if you didn't opt-in to use it, you are not impacted.\n\n### Patches\n\nPatched in `2.19.2`.\n\n### Workarounds\n\nThe issue can be avoided by not using the `allow_duplicate_key: false` parsing option.","published":"2026-03-20T22:57:08.758Z","modified":"2026-10-28T11:11:50.512810194Z","cvss":null,"epss":{"score":0.00857,"percentile":0.56708,"asOf":"2026-09-17"},"cisaKev":null,"exploitsKnown":0,"affectedPackages":[{"ecosystem":"RubyGems","name":"json","fixedVersion":"2.19.2"},{"ecosystem":"RubyGems","name":"json","fixedVersion":"2.17.1.2"},{"ecosystem":"RubyGems","name":"json","fixedVersion":"2.15.2.1"}],"fix":null,"references":[{"type":"WEB","url":"https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-33210.json"},{"type":"ADVISORY","url":"https://access.redhat.com/errata/RHSA-2026:20596"},{"type":"ADVISORY","url":"https://access.redhat.com/errata/RHSA-2026:20606"},{"type":"ADVISORY","url":"https://access.redhat.com/errata/RHSA-2026:57565"},{"type":"ADVISORY","url":"https://access.redhat.com/security/cve/CVE-2026-33210"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/33xxx/CVE-2026-33210.json"},{"type":"ADVISORY","url":"https://github.com/ruby/json/security/advisories/GHSA-3m6g-2423-7cp3"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-33210"},{"type":"REPORT","url":"https://bugzilla.redhat.com/show_bug.cgi?id=2449871"},{"type":"PACKAGE","url":"https://github.com/ruby/json"},{"type":"WEB","url":"https://github.com/rubysec/ruby-advisory-db/blob/master/gems/json/CVE-2026-33210.yml"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-10-28T11:11:50.512810194Z"}}