{ "affected": [ { "database_specific": { "last_known_affected_version_range": "< 3.17.2", "source": "https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/06/GHSA-9ppp-w3g4-fh4q/GHSA-9ppp-w3g4-fh4q.json" }, "package": { "ecosystem": "RubyGems", "name": "oj", "purl": "pkg:gem/oj" }, "ranges": [ { "events": [ { "introduced": "0" }, { "fixed": "3.17.3" } ], "type": "ECOSYSTEM" } ], "versions": [ "0.5", "0.5.1", "0.5.2", "0.6.0", "0.7.0", "0.8.0", "0.9.0", "1.0.0", "1.0.1", "1.0.2", "1.0.3", "1.0.4", "1.0.5", "1.0.6", "1.1.0", "1.1.1", "1.2.0", "1.2.1", "1.2.10", "1.2.11", "1.2.12", "1.2.13", "1.2.2", "1.2.3", "1.2.4", "1.2.5", "1.2.6", "1.2.7", "1.2.8", "1.2.9", "1.3.0", "1.3.2", "1.3.4", "1.3.5", "1.3.6", "1.3.7", "1.4.0", "1.4.1", "1.4.2", "1.4.3", "1.4.4", "1.4.5", "1.4.6", "1.4.6a2", "1.4.7", "2.0.0", "2.0.1", "2.0.10", "2.0.11", "2.0.12", "2.0.13", "2.0.14", "2.0.2", "2.0.3", "2.0.4", "2.0.5", "2.0.6", "2.0.7", "2.0.8", "2.0.9", "2.1.0", "2.1.1", "2.1.2", "2.1.3", "2.1.4", "2.1.6", "2.1.7", "2.10.0", "2.10.1", "2.10.2", "2.10.3", "2.10.4", "2.11.0", "2.11.1", "2.11.2", "2.11.3", "2.11.4", "2.11.5", "2.12.0", "2.12.1", "2.12.10", "2.12.11", "2.12.12", "2.12.13", "2.12.14", "2.12.2", "2.12.3", "2.12.4", "2.12.5", "2.12.6", "2.12.7", "2.12.8", "2.12.9", "2.13.0", "2.13.1", "2.14.0", "2.14.1", "2.14.2", "2.14.3", "2.14.4", "2.14.5", "2.14.6", "2.15.0", "2.15.1", "2.16.0", "2.16.1", "2.17.0", "2.17.1", "2.17.2", "2.17.3", "2.17.4", "2.17.5", "2.18.0", "2.18.1", "2.18.2", "2.18.3", "2.18.4", "2.18.5", "2.2.0", "2.2.1", "2.2.2", "2.2.3", "2.3.0", "2.4.0", "2.4.1", "2.4.2", "2.4.3", "2.5.1", "2.5.2", "2.5.3", "2.5.4", "2.5.5", "2.6.0", "2.6.1", "2.7.0", "2.7.1", "2.7.2", "2.7.3", "2.8.0", "2.8.1", "2.9.0", "2.9.1", "2.9.2", "2.9.3", "2.9.4", "2.9.5", "2.9.6", "2.9.7", "2.9.8", "2.9.9", "3.0.0", "3.0.1", "3.0.10", "3.0.11", "3.0.2", "3.0.3", "3.0.4", "3.0.5", "3.0.6", "3.0.7", "3.0.8", "3.0.9", "3.1.0", "3.1.2", "3.1.3", "3.1.4", "3.10.0", "3.10.1", "3.10.10", "3.10.11", "3.10.12", "3.10.13", "3.10.14", "3.10.15", "3.10.16", "3.10.17", "3.10.18", "3.10.2", "3.10.3", "3.10.5", "3.10.6", "3.10.7", "3.10.8", "3.10.9", "3.11.0", "3.11.1", "3.11.2", "3.11.3", "3.11.4", "3.11.5", "3.11.6", "3.11.7", "3.11.8", "3.12.0", "3.12.1", "3.12.2", "3.12.3", "3.13.0", "3.13.1", "3.13.10", "3.13.11", "3.13.12", "3.13.13", "3.13.14", "3.13.15", "3.13.16", "3.13.17", "3.13.18", "3.13.19", "3.13.2", "3.13.20", "3.13.21", "3.13.22", "3.13.23", "3.13.3", "3.13.4", "3.13.5", "3.13.6", "3.13.7", "3.13.8", "3.13.9", "3.14.0", "3.14.1", "3.14.2", "3.14.3", "3.15.0", "3.15.1", "3.16.0", "3.16.1", "3.16.10", "3.16.11", "3.16.12", "3.16.13", "3.16.14", "3.16.15", "3.16.16", "3.16.17", "3.16.2", "3.16.3", "3.16.4", "3.16.5", "3.16.6", "3.16.7", "3.16.8", "3.16.9", "3.17.0", "3.17.1", "3.2.0", "3.2.1", "3.3.0", "3.3.1", "3.3.10", "3.3.2", "3.3.3", "3.3.4", "3.3.5", "3.3.6", "3.3.7", "3.3.8", "3.3.9", "3.4.0", "3.5.0", "3.5.1", "3.6.0", "3.6.10", "3.6.11", "3.6.12", "3.6.13", "3.6.2", "3.6.3", "3.6.4", "3.6.5", "3.6.6", "3.6.7", "3.6.8", "3.6.9", "3.7.0", "3.7.1", "3.7.10", "3.7.11", "3.7.12", "3.7.2", "3.7.3", "3.7.4", "3.7.5", "3.7.6", "3.7.7", "3.7.8", "3.7.9", "3.8.0", "3.8.1", "3.9.0", "3.9.1", "3.9.2" ] } ], "aliases": [ "CVE-2026-54897" ], "database_specific": { "cwe_ids": [ "CWE-416" ], "github_reviewed": true, "github_reviewed_at": "2026-06-19T19:36:50Z", "nvd_published_at": null, "severity": "HIGH" }, "details": "### Summary\n\n`Oj::Doc` iterators (`each_value`, `each_child`, `each_leaf`) are vulnerable to a heap use-after-free. When a Ruby block yielded during iteration calls `doc.close` or `d.close`, the document's heap memory is freed while the C iterator is still running. When control returns from the block, the iterator reads from the freed region, producing a use-after-free accessible from pure Ruby.\n\n### Version\n\n- **Software**: oj gem\n- **Affected**: all versions with `ext/oj/fast.c`\n- **Latest tested**: 3.17.1 (confirmed present)\n\n### Details\n\nThe iterators in `ext/oj/fast.c` follow the pattern:\n\n```c\n// fast.c:1505 (doc_each_child)\nstatic VALUE doc_each_child(VALUE self, ...) {\n ...\n while (cur != NULL) {\n rb_yield(...); // ← Ruby block executes here\n cur = cur->next; // ← cur is now freed if block called close()\n }\n}\n```\n\n`rb_yield` can invoke arbitrary Ruby code, including calling `close()` on the `Doc` or any child node, which calls `ruby_sized_xfree` on the backing buffer. On return, the C code reads `cur->next` from the freed region. All three iterators are affected.\n\nASAN report (each_child variant):\n```\n==253632==ERROR: AddressSanitizer: heap-use-after-free on address 0x5210000bd080\nREAD of size 8 at 0x5210000bd080 thread T0\n #0 doc_each_child /ext/oj/fast.c:1505\n0x5210000bd080 is located 896 bytes inside of 4064-byte region [0x5210000bcd00, 0x5210000bdce0)\nfreed by thread T0 here:\n #0 free\n #1 ruby_sized_xfree (libruby-3.3.so.3.3)\n```\n\nAll three iterators trigger the same freed region (`fd` shadow bytes):\n```\n0x5210000bd080:[fd]fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd\n```\n\n### Reproduce\n\n```ruby\nrequire 'oj'\n# each_child\nOj::Doc.open('[1,2]') { |doc| doc.each_child { |d| d.close } }\n# each_value\nOj::Doc.open('[1,2]') { |doc| doc.each_value { |v| doc.close } }\n# each_leaf\nOj::Doc.open('[1,[2]]') { |doc| doc.each_leaf { |d| d.close } }\n```", "id": "GHSA-9ppp-w3g4-fh4q", "modified": "2026-09-10T03:51:08.386798324Z", "published": "2026-06-19T19:36:50Z", "references": [ { "type": "WEB", "url": "https://github.com/ohler55/oj/security/advisories/GHSA-9ppp-w3g4-fh4q" }, { "type": "PACKAGE", "url": "https://github.com/ohler55/oj" } ], "schema_version": "1.9.0", "severity": [ { "score": "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", "type": "CVSS_V4" } ], "summary": "Oj: Use-After-Free in Oj::Doc Iterators via Reentrant Close" }