CVE-2016-9838

HIGH LAB

Joomla! < 3.6.4 - Improper Access Control via Registration Form Session Data

Title source: llm
STIX 2.1

Exploitation Summary

EIP tracks 2 public exploits for CVE-2016-9838. PoCs published by Charles Fol, cved-sources.

AI-analyzed exploit summary This exploit leverages a vulnerability in Joomla! <= 3.6.4 to take over an admin account by manipulating the registration form to associate a new user with an existing admin ID. It bypasses password validation by first submitting mismatched passwords and then resubmitting with matching passwords.

Description

An issue was discovered in components/com_users/models/registration.php in Joomla! before 3.6.5. Incorrect filtering of registration form data stored to the session on a validation error enables a user to gain access to a registered user's account and reset the user's group mappings, username, and password, as demonstrated by submitting a form that targets the `registration.register` task.

Exploits (2)

exploitdb WORKING POC
by Charles Fol · pythonwebappsphp
https://www.exploit-db.com/exploits/41157

This exploit leverages a vulnerability in Joomla! <= 3.6.4 to take over an admin account by manipulating the registration form to associate a new user with an existing admin ID. It bypasses password validation by first submitting mismatched passwords and then resubmitting with matching passwords.

Classification
Working Poc 95%
Attack Type
Auth Bypass
Complexity
Moderate
Reliability
Reliable
Target: Joomla! <= 3.6.4
No auth needed
Prerequisites: Access to the Joomla! registration page · Knowledge of an existing admin user ID
devstral-2 · analyzed Feb 16, 2026 Full analysis →
nomisec WORKING POC
by cved-sources · poc
https://github.com/cved-sources/cve-2016-9838

This repository provides a Dockerized environment for Joomla 3.6.4, which is vulnerable to CVE-2016-9838. The setup includes a pre-configured Joomla installation with a database, allowing for testing of the vulnerability in an isolated container.

Classification
Working Poc 90%
Attack Type
Sqli
Complexity
Moderate
Reliability
Reliable
Target: Joomla 3.6.4
No auth needed
Prerequisites: Docker environment · Basic knowledge of Joomla exploitation
devstral-2 · analyzed Feb 18, 2026 Full analysis →

References (3)

Core 3
Core References
Exploit, Third Party Advisory exploit x_refsource_exploit-db
https://www.exploit-db.com/exploits/41157/
Third Party Advisory, VDB Entry vdb-entry x_refsource_bid
http://www.securityfocus.com/bid/94893

Scores

CVSS v3 7.5
EPSS 0.1410
EPSS Percentile 96.1%
Attack Vector NETWORK
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N

Lab Environment

COMMUNITY
Community Lab
docker pull cved/base-lamp

Details

CWE
CWE-284
Status published
Products (1)
joomla/joomla\! < 3.6.4
Published Dec 16, 2016
Tracked Since Feb 18, 2026