CVE-2026-54903
Oj: Integer Overflow in Oj.load 2GB String Handling
Description
Oj (Optimized JSON) is a JSON parser and Object marshaller packaged as a Ruby gem. In versions prior to 3.17.2, Oj.load is vulnerable to heap corruption when parsing a JSON string longer than 2 GB. An integer overflow in buf_append_string (buf.h:61) converts the string length to a large negative size_t, causing memcpy to copy an astronomically large amount of data out of bounds. This crashes the process and can corrupt adjacent heap memory. The 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 newer.
- Recompile the application if necessary.
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-2026-54903.
| URL | Resource |
|---|---|
| https://github.com/ohler55/oj/security/advisories/GHSA-475m-ph3x-64gp | |
| https://github.com/ohler55/oj/security/advisories/GHSA-475m-ph3x-64gp |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-54903 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-2026-54903
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-2026-54903 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-54903 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.
-
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.load es vulnerable a la corrupción del montón al analizar una cadena JSON de más de 2 GB. Un desbordamiento de entero en buf_append_string (buf.h:61) convierte la longitud de la cadena en un size_t negativo grande, lo que hace que memcpy copie una cantidad astronómicamente grande de datos fuera de los límites. Esto bloquea el proceso y puede corromper la memoria adyacente del montón. El problema ha sido solucionado 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-475m-ph3x-64gp Added SSVC {'id': 'CVE-2026-54903', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'poc'}, {'automatable': 'yes'}, {'technicalImpact': 'partial'}], 'version': '2.0.3', 'timestamp': '2026-07-01T12:43:29.240390Z'} -
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.load is vulnerable to heap corruption when parsing a JSON string longer than 2 GB. An integer overflow in buf_append_string (buf.h:61) converts the string length to a large negative size_t, causing memcpy to copy an astronomically large amount of data out of bounds. This crashes the process and can corrupt adjacent heap memory. The 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-190 Added Reference https://github.com/ohler55/oj/security/advisories/GHSA-475m-ph3x-64gp