CVE-2026-33210
Format String Injection in Ruby JSON Causes DoS and Data Leak
Publication date: 2026-03-20
Last updated on: 2026-03-27
Assigner: GitHub, Inc.
Description
Description
CVSS Scores
EPSS Scores
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Meta Information
Affected Vendors & Products
| Vendor | Product | Version / Range |
|---|---|---|
| ruby-lang | json | From 2.14.0 (inc) to 2.15.2.1 (exc) |
| ruby-lang | json | From 2.16.0 (inc) to 2.17.1.2 (exc) |
| ruby-lang | json | From 2.18.0 (inc) to 2.19.2 (exc) |
Helpful Resources
Exploitability
| CWE ID | Description |
|---|---|
| CWE-134 | The product uses a function that accepts a format string as an argument, but the format string originates from an external source. |
Attack-Flow Graph
AI Powered Q&A
How can this vulnerability impact me? :
The vulnerability can impact you by allowing attackers to cause denial of service conditions or to disclose sensitive information when parsing JSON documents with the affected Ruby JSON versions using the allow_duplicate_key: false option.
How does this vulnerability affect compliance with common standards and regulations (like GDPR, HIPAA)?:
I don't know
How can this vulnerability be detected on my network or system? Can you suggest some commands?
I don't know
Can you explain this vulnerability to me?
This vulnerability exists in the Ruby JSON library versions from 2.14.0 up to but not including 2.15.2.1, 2.17.1.2, and 2.19.2. It is a format string injection vulnerability that occurs when the parsing option allow_duplicate_key is set to false and user-supplied JSON documents are parsed. Exploiting this vulnerability can lead to denial of service attacks or information disclosure.
What immediate steps should I take to mitigate this vulnerability?
To mitigate this vulnerability, upgrade Ruby JSON to a patched version. Specifically, update to version 2.15.2.1, 2.17.1.2, or 2.19.2 or later, where the format string injection issue has been fixed.