CVE-2026-54901
Oj: Use-After-Free in Oj::Parser array_class/hash_class GC Marking
- State
- Published
- Severity
- 6.3 Medium
- Published
- Jun 30, 2026
- Updated
- Jul 1, 2026
- Reserved
- Jun 16, 2026
Description
Oj (Optimized JSON) is a JSON parser and Object marshaller packaged as a Ruby gem. In versions prior to 3.17.2, Oj::Parser in usual mode does not mark array_class and hash_class references during garbage collection, leading to Use-After-Free. If GC runs after the class is assigned but before a parse, the class object is reclaimed, leaving the parser holding a dangling VALUE. The subsequent parse call dereferences the freed object, producing a segfault. This issue has been fixed in version 3.17.2.
Scores
| CVSS | Score | Vector | Source |
|---|---|---|---|
| 4.0 | 6.3 Medium | CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N | GitHub_M |
Weaknesses
- CWE-416 Use After Free
Affected Products
| Product | Versions |
|---|---|
ojohler55 |
|
References
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