VDB-352234 · CVE-2026-33210 · GHSA-3m6g-2423-7cp3

Ruby json up to 2.19.1 allow_duplicate_key format string

CVSS Meta Temp Score CVSS is a standardized scoring system to determine possibilities of attacks. The Temp Score considers temporal factors like disclosure, exploit and countermeasures. The unique Meta Score calculates the average score of different sources to provide a normalized scoring system.	Current Exploit Price (≈) Our analysts are monitoring exploit markets and are in contact with vulnerability brokers. The range indicates the observed or calculated exploit price to be seen on exploit markets. A good indicator to understand the monetary effort required for and the popularity of an attack.	CTI Interest Score Our Cyber Threat Intelligence team is monitoring different web sites, mailing lists, exploit markets and social media networks. The CTI Interest Score identifies the interest of attackers and the security community for this specific vulnerability in real-time. A high score indicates an elevated risk to be targeted for this vulnerability.
8.0	$0-$5k	0.00

Summaryinfo

A vulnerability categorized as critical has been discovered in Ruby json up to 2.19.1. This vulnerability affects the function allow_duplicate_key. Executing a manipulation can lead to format string. The identification of this vulnerability is CVE-2026-33210. The attack may be launched remotely. There is no exploit available. It is advisable to upgrade the affected component.

Detailsinfo

A vulnerability classified as critical was found in Ruby json up to 2.19.1. This vulnerability affects the function allow_duplicate_key. The manipulation with an unknown input leads to a format string vulnerability. The CWE definition for the vulnerability is CWE-134. The product uses a function that accepts a format string as an argument, but the format string originates from an external source. As an impact it is known to affect confidentiality, integrity, and availability. CVE summarizes:

Ruby JSON is a JSON implementation for Ruby. From version 2.14.0 to before versions 2.15.2.1, 2.17.1.2, and 2.19.2, a format string injection vulnerability can lead to denial of service attacks or information disclosure, when the allow_duplicate_key: false parsing option is used to parse user supplied documents. This issue has been patched in versions 2.15.2.1, 2.17.1.2, and 2.19.2.

The advisory is available at github.com. This vulnerability was named CVE-2026-33210 since 03/18/2026. The exploitation appears to be easy. The attack can be initiated remotely. No form of authentication is required for a successful exploitation. Technical details are known, but there is no available exploit.

The vulnerability scanner Nessus provides a plugin with the ID 303258 (Linux Distros Unpatched Vulnerability : CVE-2026-33210), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 2.15.2.1, 2.17.1.2 or 2.19.2 eliminates this vulnerability.

The vulnerability is also documented in the vulnerability database at Tenable (303258). If you want to get best quality of vulnerability data, you may have to visit VulDB.

Productinfo

Type

Programming Language Software

Vendor

Ruby

Name

json

Version

License

open-source

Website

Product: https://github.com/ruby/json/

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CNA CVSS-B Score: 🔒
CNA CVSS-BT Score: 🔒
CNA Vector: 🔒

CVSSv3info

VulDB Meta Base Score: 8.2
VulDB Meta Temp Score: 8.0

VulDB Base Score: 7.3
VulDB Temp Score: 7.0
VulDB Vector: 🔒
VulDB Reliability: 🔍

NVD Base Score: 9.1
NVD Vector: 🔒

CVSSv2info

AV	AC	Au	C	I	A
💳	💳	💳	💳	💳	💳
💳	💳	💳	💳	💳	💳
💳	💳	💳	💳	💳	💳

Vector	Complexity	Authentication	Confidentiality	Integrity	Availability
Unlock	Unlock	Unlock	Unlock	Unlock	Unlock
Unlock	Unlock	Unlock	Unlock	Unlock	Unlock
Unlock	Unlock	Unlock	Unlock	Unlock	Unlock

VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Format string
CWE: CWE-134 / CWE-119
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Yes

Availability: 🔒
Status: Not defined

EPSS Score: 🔒
EPSS Percentile: 🔒

Price Prediction: 🔍
Current Price Estimation: 🔒

0-Day	Unlock	Unlock	Unlock	Unlock
Today	Unlock	Unlock	Unlock	Unlock

Nessus ID: 303258
Nessus Name: Linux Distros Unpatched Vulnerability : CVE-2026-33210

Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: json 2.15.2.1/2.17.1.2/2.19.2

Timelineinfo

03/18/2026 CVE reserved
03/21/2026 +3 days Advisory disclosed
03/21/2026 +0 days VulDB entry created
03/27/2026 +6 days VulDB entry last update

Sourcesinfo

Product: github.com

Advisory: GHSA-3m6g-2423-7cp3
Status: Confirmed

CVE: CVE-2026-33210 (🔒)
GCVE (CVE): GCVE-0-2026-33210
GCVE (VulDB): GCVE-100-352234

Entryinfo

Created: 03/21/2026 07:43
Updated: 03/27/2026 22:30
Changes: 03/21/2026 07:43 (69), 03/22/2026 18:30 (2), 03/27/2026 06:05 (1), 03/27/2026 22:30 (11)
Complete: 🔍
Cache ID: 216::103

If you want to get best quality of vulnerability data, you may have to visit VulDB.