CVE-2026-54900 - Vulnerability Details

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 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.

Published: 2026-06-30

Score: 6.3 Medium

EPSS: n/a

KEV: No

Impact:

Action:

Analysis

Analysis and contextual insights are available on OpenCVE Cloud.

Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).

Vendor Product Default status Versions

ohler55

affected

Version	Status	Constraints
`< 3.17.2`	affected	—

No data.

No data available yet.

Remediation

No vendor fix or workaround currently provided.

Additional remediation guidance may be available on OpenCVE Cloud.

Tracking

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Advisories

Source	ID	Title
Github GHSA	GHSA-9cv6-qcjw-4grx	Oj: Negative-Size memcpy in Oj::Parser create_id Attribute Handling

Attack Vector Network

Attack Complexity Low

Privileges Required None

Attack Requirements Present

User Interaction None

Vulnerable System Confidentiality Impact None

Vulnerable System Integrity Impact None

Vulnerable System Availability Impact Low

Subsequent System Confidentiality Impact None

Subsequent System Integrity Impact None

Subsequent System Availability Impact None

No CVSS v3.1

No CVSS v3.0

No CVSS v2

This CVE is not in the KEV list.

No EPSS score available.

Key SSVC decision points have not yet been added.

References

Link	Providers
https://github.com/ohler55/oj/security/advisories/GHSA-9cv6-qcjw-4grx

History

Tue, 30 Jun 2026 23:45:00 +0000

Type	Values Removed	Values Added
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 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.
Title		Oj: Negative-Size memcpy in Oj::Parser create_id Attribute Handling
Weaknesses		CWE-190 CWE-787
References		https://github.com/ohler55/oj/security/advisories/GHSA-9cv6-qcjw-4grx
Metrics		cvssV4_0 `{'score': 6.3, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N'}`

Subscriptions

No data.

MITRE

Status: PUBLISHED

Assigner: GitHub_M

Published: 2026-06-30T23:34:05.904Z

Updated: 2026-06-30T23:34:05.904Z

Reserved: 2026-06-16T13:49:33.555Z

Link: CVE-2026-54900

Vulnrichment

No data.

NVD

No data.

Redhat

No data.

OpenCVE Enrichment

Updated: 2026-07-01T01:15:16Z

Weaknesses