CVE-2026-54901
Oj: Use-After-Free in Oj::Parser array_class/hash_class GC Marking
CVSS Score
0.0
EPSS Score
0.0%
EPSS Percentile
0th
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.
| CWE | CWE-416 |
| Vendor | ohler55 |
| Product | oj |
| Published | Jun 30, 2026 |
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Affected Versions
ohler55 / oj
< 3.17.2