CVE-2026-54502
Oj: Stack Buffer Overflow in Oj.dump 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, Oj.dump is vulnerable to a stack-based buffer overflow when a large :indent value is provided by the developer. fill_indent in dump.h calls memset(indent_str, ' ', (size_t)opts->indent) without validating the size. When opts->indent is set to INT_MAX (2,147,483,647), the (size_t) cast preserves the large value and memset writes 2 GB into the stack-allocated out buffer (4,184 bytes), corrupting the stack and crashing the process. This issue has been fixed in version 3.17.2.
INFO
Published Date :
July 1, 2026, 12:16 a.m.
Last Modified :
Oct. 25, 2026, 5:10 p.m.
Remotely Exploit :
Yes !
Source :
[email protected]
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS | 134c704f-9b21-4f2e-91b3-4a467353bcc0 | |||||
| CVSS 4.0 | MEDIUM | [email protected] |
Solution
- Update the Oj gem to version 3.17.2 or later.
- Ensure proper validation of user-supplied :indent values.
- Avoid using excessively large :indent values.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-54502.
| URL | Resource |
|---|---|
| https://github.com/ohler55/oj/security/advisories/GHSA-3v45-f3vh-wg7m | |
| https://github.com/ohler55/oj/security/advisories/GHSA-3v45-f3vh-wg7m |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-54502 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-54502
weaknesses.
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).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-54502 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-54502 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
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CVE Translated by [email protected]
Oct. 25, 2026
Action Type Old Value New Value Added Translation Title: oj de ohler55, Description: Oj (JSON Optimizado) es un analizador JSON y un serializador de objetos empaquetado como una gema de Ruby. En versiones anteriores a la 3.17.2, Oj.dump es vulnerable a un desbordamiento de búfer basado en pila cuando el desarrollador proporciona un valor :indent grande. fill_indent en dump.h llama a memset(indent_str, ’ ’, (size_t)opts -> indent) sin validar el tamaño. Cuando opts -> indent se establece en INT_MAX (2.147.483.647), la conversión (size_t) preserva el valor grande y memset escribe 2 GB en el búfer de salida asignado en la pila (4.184 bytes), corrompiendo la pila y bloqueando el proceso. Este problema ha sido corregido en la versión 3.17.2. -
CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0
Jul. 01, 2026
Action Type Old Value New Value Added Reference https://github.com/ohler55/oj/security/advisories/GHSA-3v45-f3vh-wg7m Added SSVC {'id': 'CVE-2026-54502', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'poc'}, {'automatable': 'yes'}, {'technicalImpact': 'total'}], 'version': '2.0.3', 'timestamp': '2026-07-01T15:49:45.690933Z'} -
New CVE Received by [email protected]
Jul. 01, 2026
Action Type Old Value New Value Added Affected [{'vendor': 'ohler55', 'product': 'oj', 'versions': [{'status': 'affected', 'version': '< 3.17.2'}]}] Added Description Oj (Optimized JSON) is a JSON parser and Object marshaller packaged as a Ruby gem. In versions prior to 3.17.2, Oj.dump is vulnerable to a stack-based buffer overflow when a large :indent value is provided by the developer. fill_indent in dump.h calls memset(indent_str, ' ', (size_t)opts->indent) without validating the size. When opts->indent is set to INT_MAX (2,147,483,647), the (size_t) cast preserves the large value and memset writes 2 GB into the stack-allocated out buffer (4,184 bytes), corrupting the stack and crashing the process. This issue has been fixed in version 3.17.2. Added CVSS V4.0 AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X Added CWE CWE-121 Added Reference https://github.com/ohler55/oj/security/advisories/GHSA-3v45-f3vh-wg7m