CVE-2026-54897 LOW

CVE-2026-54897: Oj : Use-After-Free in Oj::Doc Iterators via Reentrant Close

Vendor Ohler55
Product oj
Weakness CWE-416
Published June 30, 2026
Last update July 1, 2026

CVSS base score

2.1/10
Attack vector Local
Attack complexity Low
Privileges required None
User interaction None
Confidentiality
Integrity

CVSS vector

CVSS:4.0/AV:L/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N

What the vulnerability does

01Description

Oj (Optimized JSON) is a JSON parser and Object marshaller packaged as a Ruby gem. Prior to 3.17.2, Oj::Doc iterators (each_value, each_child, each_leaf) were vulnerable to a heap use-after-free. When a Ruby block yielded during iteration calls doc.close or d.close, the document's heap memory is freed while the C iterator is still running. When control returns from the block, the iterator reads from the freed region, producing a use-after-free accessible from pure Ruby. This issue has been fixed in version 3.17.2.

Key dates

02Disclosure timeline

June 30, 2026 CVE published
July 1, 2026 Record updated