CVE-2026-54896CWE-122

Oj: Heap Buffer Overflow in Oj.dump Exception Serialization via Large Indent

Low · published June 30, 2026

CVSS v4.0
2.1
EPSS
0%
Percentile
3.7
In the wild
Unconfirmed
What it is

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.

The record
Technical detail
CVSS v4.0
2.1 · LOW
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
EPSS
0.00148 · 3.7th percentile
Weakness
CWE-122 · Heap-based Buffer Overflow
Published
2026-06-30T23:20Z
EPSS history
Timeline
  • 30 JUN 23:20Z
    Oj: Heap Buffer Overflow in Oj.dump Exception Serialization via Large Indent
    cvelistv5