CVE-2026-54900 – Oj: Negative-Size memcpy in Oj::Parser create_id Attribute Handling

CVE ID :CVE-2026-54900

Published : June 30, 2026, 11:34 p.m. | 12 minutes ago

Description :Oj (Optimized JSON) is a JSON parser and Object marshaller packaged as a Ruby gem. In versions prior to 3.17.2, when in usual mode with create_id enabled, Oj::Parser#parse is vulnerable to heap corruption via a negative-size memcpy. When a JSON object key is exactly 65,535 bytes long, an integer truncation in form_attr (usual.c:63) converts the length to -1 before passing it to memcpy. This causes memcpy to copy SIZE_MAX bytes (interpreted as a huge size_t), corrupting heap memory and crashing the process. The issue has been fixed in version 3.17.2.

Severity: 0.0 | NA

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