CVE-2026-54896 LOW

CVE-2026-54896: Oj: Heap Buffer Overflow in Oj.dump Exception Serialization via Large Indent

Vendor Ohler55
Product oj
Weakness CWE-122
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. In versions prior to 3.17.2, when in object mode, Oj.dump is vulnerable to a heap buffer overflow when serializing Exception objects with a large :indent value. The serializer allocates a buffer sized for the object's attributes but does not account for the indent bytes added on each write. With indent: 5000, the accumulation of 5,000-byte indent strings overflows the 13,150-byte heap allocation, corrupting adjacent heap memory. This issue has been fixed in version 3.17.2.

Key dates

02Disclosure timeline

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