ohler55 oj up to 3.17.1 JSON Parser usual.c Oj::Parser#parse integer overflow

Summaryinfo

A vulnerability was found in ohler55 oj up to 3.17.1. It has been declared as problematic. The affected element is the function Oj::Parser#parse of the file usual.c of the component JSON Parser. Such manipulation leads to integer overflow. This vulnerability is documented as CVE-2026-54900. The attack can be executed remotely. There is not any exploit available. It is recommended to upgrade the affected component.

Detailsinfo

A vulnerability, which was classified as problematic, has been found in ohler55 oj up to 3.17.1. Affected by this issue is the function Oj::Parser#parse of the file usual.c of the component JSON Parser. The manipulation with an unknown input leads to a integer overflow vulnerability. Using CWE to declare the problem leads to CWE-190. The product performs a calculation that can produce an integer overflow or wraparound, when the logic assumes that the resulting value will always be larger than the original value. This can introduce other weaknesses when the calculation is used for resource management or execution control. Impacted is availability. CVE summarizes:

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.

The advisory is shared for download at github.com. This vulnerability is handled as CVE-2026-54900 since 06/16/2026. The exploitation is known to be easy. The attack may be launched remotely. No form of authentication is required for exploitation. There are known technical details, but no exploit is available.

Upgrading to version 3.17.2 eliminates this vulnerability.

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Productinfo

Vendor

• ohler55

Name

• oj

Version

• 3.17.0
• 3.17.1

Website

• Product: https://github.com/ohler55/oj/

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