0.0
NA
CVE-2026-54896
Oj: Heap Buffer Overflow in Oj.dump Exception Serialization via Large Indent
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 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.

INFO

Published Date :

June 30, 2026, 11:20 p.m.

Last Modified :

June 30, 2026, 11:20 p.m.

Remotely Exploit :

No

Source :

GitHub_M
Affected Products

The following products are affected by CVE-2026-54896 vulnerability. Even if cvefeed.io is aware of the exact versions of the products that are affected, the information is not represented in the table below.

No affected product recoded yet

Solution
Update Oj gem to version 3.17.2 or later to fix heap buffer overflow vulnerability.
  • Update the Oj gem to version 3.17.2.
  • Verify the installed gem version.

We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).

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EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days. Following chart shows the EPSS score history of the vulnerability.