{"cve":"CVE-2026-71847","nvd":{"published":"2026-08-07T19:18:53.807","modified":"2026-10-24T15:10:00.190","status":"Awaiting Analysis","description":"Ruby JSON is a JSON implementation for Ruby. From 2.20.0 until 2.21.2, Ruby's JSON native C extension clears the consumed JSON::ResumableParser input buffer but leaves state.start, state.cursor, and state.end pointing into released storage. When partial_value reconstructs an incomplete object containing duplicate keys, the duplicate-key warning path calls cursor_position, which dereferences those stale pointers. This results in a heap-use-after-free and can terminate the Ruby process. An attacker who can supply JSON stream data to an application using JSON::ResumableParser may cause process termination when the application calls partial_value on incomplete attacker-controlled input containing duplicate object keys. This issue has been fixed in version 2.21.2.","cvss_v4":{"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N","score":8.7},"cvss_v3":null,"cwes":["CWE-416"],"references":["https://github.com/ruby/json/security/advisories/GHSA-9hj4-r449-hfvc","https://github.com/ruby/json/security/advisories/GHSA-9hj4-r449-hfvc"],"products":[],"source":"nvd","synced_at":"2026-10-24T16:53:34.184483516+00:00"},"epss":{"cve":"CVE-2026-71847","score":0.00428,"percentile":0.36759,"date":"2026-10-25"},"kev":null,"osv":[{"id":"GHSA-9hj4-r449-hfvc","url":"https://osv.dev/vulnerability/GHSA-9hj4-r449-hfvc","summary":"Ruby JSON: JSON::ResumableParser#partial_value dereferences a freed input buffer and crashes on truncated duplicate-key streams","modified":"2026-09-10T03:51:13.782635464Z","packages":[{"ecosystem":"RubyGems","name":"json","purl":"pkg:gem/json","ranges":[">=2.20.0 <2.21.2"],"fixed":["2.21.2"]}]}],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}