CVE-2026-54500

EIP tracks 1 public exploit for CVE-2026-54500. PoCs published by HermesNA-1.

AI-analyzed exploit summary This repository contains an auto-generated stub module for CVE-2026-54500, a memory leak vulnerability in the Oj Ruby gem (versions prior to 3.17.3). The module includes placeholder code for a potential exploit but lacks actual PoC implementation, referencing only advisory details.

Oj (Optimized JSON) is a JSON parser and Object marshaller packaged as a Ruby gem. In versions prior to 3.17.3, Oj.load in :object mode reads uninitialized stack memory (and, for long keys, reads out of bounds) when parsing a JSON object whose key is 254 bytes or longer. The interned bytes can surface to the caller, disclosing process stack memory. In ext/oj/intern.c, form_attr() handles the long-key path by allocating a heap buffer, `b`, populating it with the attribute name, and then freeing it — but it passed the uninitialized stack buffer buf (not b) to rb_intern3(). rb_intern3 therefore reads len + 1 bytes of uninitialized stack memory. When the key length is >= 256, it also reads out of bounds past the 256-byte buf. The resulting bytes are interned and can reach the caller via the produced Symbol or via the EncodingError message raised on invalid UTF-8, leaking process stack contents. This issue has been fixed in version 3.17.3.