{"cve":"CVE-2026-54500","nvd":{"published":"2026-07-01T00:16:32.147","modified":"2026-10-25T17:10:00.197","status":"Deferred","description":"Oj (Optimized JSON) is a JSON parser and Object marshaller packaged as a Ruby gem. In versions prior to 3.17.3, Oj.load in :object mode reads uninitialized stack memory (and, for long keys, reads out of bounds) when parsing a JSON object whose key is 254 bytes or longer. The interned bytes can surface to the caller, disclosing process stack memory. In ext/oj/intern.c, form_attr() handles the long-key path by allocating a heap buffer, `b`, populating it with the attribute name, and then freeing it — but it passed the uninitialized stack buffer buf (not b) to rb_intern3(). rb_intern3 therefore reads len + 1 bytes of uninitialized stack memory. When the key length is >= 256, it also reads out of bounds past the 256-byte buf. The resulting bytes are interned and can reach the caller via the produced Symbol or via the EncodingError message raised on invalid UTF-8, leaking process stack contents. This issue has been fixed in version 3.17.3.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N","score":5.3},"cwes":["CWE-125","CWE-908"],"references":["https://github.com/ohler55/oj/security/advisories/GHSA-fm7p-mprw-wjm9"],"products":[],"source":"nvd","synced_at":"2026-10-25T17:50:06.907763985+00:00"},"epss":{"cve":"CVE-2026-54500","score":0.00198,"percentile":0.09396,"date":"2026-10-25"},"kev":null,"osv":[{"id":"GHSA-fm7p-mprw-wjm9","url":"https://osv.dev/vulnerability/GHSA-fm7p-mprw-wjm9","summary":"Oj: intern.c form_attr (uninitialized stack read)","modified":"2026-09-10T03:50:49.506149539Z","packages":[{"ecosystem":"RubyGems","name":"oj","purl":"pkg:gem/oj","ranges":["<3.17.3"],"fixed":["3.17.3"]}]}],"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."]}