CVE-2026-77997 Overview
CVE-2026-77997 is an authenticated information disclosure vulnerability in the YOOtheme Pro extension for Joomla. The flaw affects versions 1.0.0 through 5.0.41 and stems from a missing access check in the extension's template editing workflow. Users granted com_template editing permissions can retrieve information about arbitrary Joomla modules without holding the corresponding com_modules permissions. The vulnerability maps to [CWE-284] Improper Access Control and requires an authenticated account with elevated privileges to exploit.
Critical Impact
Privileged Joomla users with template editing rights can enumerate module configuration data across the site, bypassing the module permission model enforced by com_modules.
Affected Products
- YOOtheme Pro for Joomla, versions 1.0.0 through 5.0.41
- Joomla sites using the YOOtheme Pro page builder extension
- Multi-user Joomla deployments delegating template administration to non-administrator roles
Discovery Timeline
- 2026-08-25 - CVE-2026-77997 published to NVD
- 2026-08-26 - Last updated in NVD database
Technical Details for CVE-2026-77997
Vulnerability Analysis
YOOtheme Pro is a commercial page builder and template extension for Joomla. The extension exposes functionality that lets template editors interact with site modules through its builder interface. Joomla enforces separate permission components for templates (com_template) and modules (com_modules), and each component is expected to check its own access rights before returning data.
The vulnerability arises because YOOtheme Pro reads module data on behalf of the template editor without re-validating the caller's com_modules permissions. A user with template editing rights can therefore query module metadata and configuration values regardless of whether they were granted module access. The disclosed data is limited to confidentiality impact only; integrity and availability are not affected. Exploitation requires an authenticated session with high privileges, which reduces the practical attack surface to insider or account-takeover scenarios.
Root Cause
The root cause is a missing authorization check on the code path that returns module information to the YOOtheme Pro builder. The extension trusts the presence of com_template permissions as sufficient authority to read module records, rather than performing a component-scoped check against com_modules before returning results.
Attack Vector
An attacker must first obtain a Joomla account with com_template editing permissions. Using that session, the attacker interacts with YOOtheme Pro endpoints that surface module data inside the builder. The response discloses module configuration for modules the account is not authorized to view under the standard Joomla ACL. No user interaction from an administrator is required, and the attack is delivered over the network against the Joomla application.
No verified proof-of-concept code is published for this issue. See the YOOtheme official website for vendor documentation and update notes.
Detection Methods for CVE-2026-77997
Indicators of Compromise
- Requests to YOOtheme Pro builder endpoints originating from user accounts that hold template rights but not module rights
- Unexpected read access to module records logged against non-administrator sessions
- Access log entries showing YOOtheme Pro API calls returning module identifiers outside the caller's assigned scope
Detection Strategies
- Correlate Joomla ACL role assignments against web server access logs to identify template editors reading module data
- Enable Joomla debug and action logging for com_modules and template components to capture cross-component reads
- Review database query logs for module table access initiated from YOOtheme Pro controllers under non-admin sessions
Monitoring Recommendations
- Alert on new or elevated com_template permission grants to non-administrator user groups
- Monitor YOOtheme Pro request volumes per user and flag accounts that enumerate large numbers of module records
- Track version strings of the YOOtheme Pro extension across managed Joomla sites to identify unpatched installations
How to Mitigate CVE-2026-77997
Immediate Actions Required
- Inventory all Joomla sites running YOOtheme Pro and identify installations at version 5.0.41 or earlier
- Update YOOtheme Pro to a release later than 5.0.41 once the vendor patch is applied
- Audit user groups that hold com_template editing rights and remove unnecessary assignments
- Rotate credentials for privileged template editor accounts if abuse is suspected
Patch Information
YOOtheme addresses the missing access check in versions later than 5.0.41. Refer to the YOOtheme official website for the current release and changelog. Apply the update through the Joomla extension manager and verify the installed version after upgrade.
Workarounds
- Restrict com_template editing to trusted administrators until the patched version is deployed
- Disable or uninstall YOOtheme Pro on sites where template editing cannot be limited to full administrators
- Apply web application firewall rules to block access to YOOtheme Pro builder endpoints from non-administrator sessions
# Configuration example: identify vulnerable YOOtheme Pro installations
grep -R "version" /path/to/joomla/administrator/components/com_yootheme/ \
| grep -Ei "5\.0\.[0-9]+|[1-4]\.[0-9]+\.[0-9]+"
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
