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 ...

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...

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...

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...

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...