CVE-2026-54901

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 arrayclass and hashclass references during garbage collection, leading to Use-After-Free. If GC runs after the class is assigned but before a parse,...

UBUNTU-CVE-2026-54901

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 arrayclass and hashclass references during garbage collection, leading to Use-After-Free. If GC runs after the class is assigned but before a parse,...

CVE-2026-54901 Oj: Use-After-Free in Oj::Parser array_class/hash_class GC Marking

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 arrayclass and hashclass references during garbage collection, leading to Use-After-Free. If GC runs after the class is assigned but before a parse,...

CVE-2026-54901

Oj (Optimized JSON) Ruby gem contains a Use-After-Free in Oj::Parser in normal mode prior to 3.17.2: during GC, array_class/hash_class refs may be reclaimed, leaving a dangling VALUE for the next parse and causing a segfault. Fixed in version 3.17.2. Affected: Oj::Parser parsing flow; trigger is ...

GHSA-VWM4-62GF-X745 Oj: Use-After-Free in Oj::Parser array_class/hash_class GC Marking

Summary Oj::Parser in usual mode does not mark arrayclass and hashclass references during garbage collection. 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...

Oj: Use-After-Free in Oj::Parser array_class/hash_class GC Marking

Summary Oj::Parser in usual mode does not mark arrayclass and hashclass references during garbage collection. 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...

Use After Free

Overview Affected versions of this package are vulnerable to Use After Free in the parsermark. An attacker can cause a segmentation fault and potentially crash the application by triggering garbage collection after assigning a custom class to arrayclass or hashclass and before parsing, leading to...

PT-2026-51087

Name of the Vulnerable Software and Affected Versions Oj versions prior to 3.17.2 Description Oj::Parser in usual mode fails to mark array class and hash class references during garbage collection GC, resulting in a Use-After-Free condition. If the GC executes after the class is assigned but befo...

Oj- Use-After-Free in 'Oj::Parser' array_class/hash_class GC Marking

Summary Oj::Parser in usual mode does not mark arrayclass and hashclass references during garbage collection. 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...