CVE-2026-54900

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 (CVSS)

Weaknesses

• CWE-190 — CWE-190: Integer Overflow or Wraparound
• CWE-787 — CWE-787: Out-of-bounds Write

Affected products

References

• https://github.com/ohler55/oj/security/advisories/GHSA-9cv6-qcjw-4grx (x_refsource_CONFIRM)