CVE-2026-33439
Pre-Authentication Remote Code Execution via `jato.clientSession` Deserialization in OpenAM
Description
Open Access Management (OpenAM) is an access management solution. Prior to 16.0.6, OpenIdentityPlatform OpenAM is vulnerable to pre-authentication Remote Code Execution (RCE) via unsafe Java deserialization of the jato.clientSession HTTP parameter. This bypasses the WhitelistObjectInputStream mitigation that was applied to the jato.pageSession parameter after CVE-2021-35464. An unauthenticated attacker can achieve arbitrary command execution on the server by sending a crafted serialized Java object as the jato.clientSession GET/POST parameter to any JATO ViewBean endpoint whose JSP contains <jato:form> tags (e.g., the Password Reset pages). This vulnerability is fixed in 16.0.6.
INFO
Published Date :
April 7, 2026, 9:17 p.m.
Last Modified :
July 24, 2026, 11:10 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 3.1 | CRITICAL | [email protected] | ||||
| CVSS 4.0 | CRITICAL | [email protected] |
Solution
- Update OpenAM to version 16.0.6.
- Apply vendor patches if available.
- Validate updated configurations.
- Monitor for suspicious activity.
Public PoC/Exploit Available at Github
CVE-2026-33439 has a 4 public
PoC/Exploit available at Github.
Go to the Public Exploits tab to see the list.
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-2026-33439.
| URL | Resource |
|---|---|
| https://github.com/OpenIdentityPlatform/OpenAM/security/advisories/GHSA-2cqq-rpvq-g5qj | Exploit Vendor Advisory |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-33439 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-2026-33439
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).
First publicly shared exploit implementation for CVE-2026-33439 (OpenAM pre-auth RCE via jato.clientSession deserialization).
java-deserialization cve-2026-33439 exploit
Python
CVE-2026-33439
Shell Java
Vulnerable endpoint description for CVE-2026-33439 in OpenAM
一个 CVE 漏洞预警知识库，无 exp/poc，部分包含修复方案。A knowledge base of CVE security vulnerability, no PoCs/exploits.
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-33439 vulnerability anywhere in the article.
-
Daily CyberSecurity
Critical Pre-Auth RCE Found in OpenAM Identity Platform
OpenAM, the widely-deployed open-source access management solution, is facing a critical security challenge following the discovery of a pre-authentication Remote Code Execution (RCE) vulnerability. T ... Read more
The following table lists the changes that have been made to the
CVE-2026-33439 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]
Jul. 24, 2026
Action Type Old Value New Value Changed Translation Title: OpenAM de OpenIdentityPlatform, Description: Open Access Management (OpenAM) es una solución de gestión de acceso. Antes de la versión 16.0.6, OpenIdentityPlatform OpenAM es vulnerable a la Ejecución Remota de Código (RCE) de pre-autenticación a través de deserialización Java insegura del parámetro HTTP jato.clientSession. Esto elude la mitigación WhitelistObjectInputStream que se aplicó al parámetro jato.pageSession después de CVE-2021-35464. Un atacante no autenticado puede lograr la ejecución arbitraria de comandos en el servidor enviando un objeto Java serializado manipulado como el parámetro GET/POST jato.clientSession a cualquier punto final JATO ViewBean cuyo JSP contiene etiquetas <jato:form> (por ejemplo, las páginas de Restablecimiento de Contraseña). Esta vulnerabilidad está corregida en la versión 16.0.6. Title: OpenAM de OpenIdentityPlatform, Description: Open Access Management (OpenAM) es una solución de gestión de acceso. Antes de la versión 16.0.6, OpenIdentityPlatform OpenAM es vulnerable a la Ejecución Remota de Código (RCE) de pre-autenticación a través de deserialización Java insegura del parámetro HTTP jato.clientSession. Esto elude la mitigación WhitelistObjectInputStream que se aplicó al parámetro jato.pageSession después de CVE-2021-35464. Un atacante no autenticado puede lograr la ejecución arbitraria de comandos en el servidor enviando un objeto Java serializado manipulado como el parámetro GET/POST jato.clientSession a cualquier punto final JATO ViewBean cuyo JSP contiene etiquetas <jato:form> (por ejemplo, las páginas de Restablecimiento de Contraseña). Esta vulnerabilidad está corregida en la versión 16.0.6. -
CVE Translated by [email protected]
Jul. 24, 2026
Action Type Old Value New Value Added Translation Title: OpenAM de OpenIdentityPlatform, Description: Open Access Management (OpenAM) es una solución de gestión de acceso. Antes de la versión 16.0.6, OpenIdentityPlatform OpenAM es vulnerable a la Ejecución Remota de Código (RCE) de pre-autenticación a través de deserialización Java insegura del parámetro HTTP jato.clientSession. Esto elude la mitigación WhitelistObjectInputStream que se aplicó al parámetro jato.pageSession después de CVE-2021-35464. Un atacante no autenticado puede lograr la ejecución arbitraria de comandos en el servidor enviando un objeto Java serializado manipulado como el parámetro GET/POST jato.clientSession a cualquier punto final JATO ViewBean cuyo JSP contiene etiquetas <jato:form> (por ejemplo, las páginas de Restablecimiento de Contraseña). Esta vulnerabilidad está corregida en la versión 16.0.6. -
CVE Modified by [email protected]
Jun. 17, 2026
Action Type Old Value New Value Added Affected [{'vendor': 'OpenIdentityPlatform', 'product': 'OpenAM', 'versions': [{'status': 'affected', 'version': '< 16.0.6'}]}] -
CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0
Jun. 17, 2026
Action Type Old Value New Value Added SSVC {'id': 'CVE-2026-33439', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'none'}, {'automatable': 'yes'}, {'technicalImpact': 'total'}], 'version': '2.0.3', 'timestamp': '2026-04-08T16:11:05.727049Z'} -
Initial Analysis by [email protected]
Apr. 15, 2026
Action Type Old Value New Value Added CVSS V3.1 AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H Added CPE Configuration OR *cpe:2.3:a:openidentityplatform:openam:*:*:*:*:*:*:*:* versions up to (excluding) 16.0.6 Added Reference Type GitHub, Inc.: https://github.com/OpenIdentityPlatform/OpenAM/security/advisories/GHSA-2cqq-rpvq-g5qj Types: Exploit, Vendor Advisory -
New CVE Received by [email protected]
Apr. 07, 2026
Action Type Old Value New Value Added Description Open Access Management (OpenAM) is an access management solution. Prior to 16.0.6, OpenIdentityPlatform OpenAM is vulnerable to pre-authentication Remote Code Execution (RCE) via unsafe Java deserialization of the jato.clientSession HTTP parameter. This bypasses the WhitelistObjectInputStream mitigation that was applied to the jato.pageSession parameter after CVE-2021-35464. An unauthenticated attacker can achieve arbitrary command execution on the server by sending a crafted serialized Java object as the jato.clientSession GET/POST parameter to any JATO ViewBean endpoint whose JSP contains <jato:form> tags (e.g., the Password Reset pages). This vulnerability is fixed in 16.0.6. Added CVSS V4.0 AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/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-502 Added Reference https://github.com/OpenIdentityPlatform/OpenAM/security/advisories/GHSA-2cqq-rpvq-g5qj