CVE-2026-31915: Flatsome Theme Authorization Bypass Flaw

CVE-2026-31915 Overview

A Missing Authorization vulnerability has been discovered in the UX-themes Flatsome WordPress theme. This broken access control flaw allows attackers to exploit incorrectly configured access control security levels, potentially enabling unauthorized actions within WordPress sites running affected versions of the Flatsome theme.

Critical Impact

Unauthenticated attackers can bypass access controls to perform unauthorized modifications on WordPress sites using the Flatsome theme through version 3.19.6.

Affected Products

• UX-themes Flatsome WordPress Theme versions through 3.19.6

Discovery Timeline

• 2026-03-13 - CVE CVE-2026-31915 published to NVD
• 2026-03-16 - Last updated in NVD database

Technical Details for CVE-2026-31915

Vulnerability Analysis

This vulnerability is classified as CWE-862 (Missing Authorization), indicating that the Flatsome theme fails to properly verify whether a user is authorized to perform certain actions. The flaw exists because specific functionality within the theme does not implement adequate permission checks, allowing any user—including unauthenticated visitors—to access or modify resources that should be restricted to authenticated or privileged users.

The network-accessible nature of this vulnerability means it can be exploited remotely without requiring prior authentication or user interaction. While the impact is limited to integrity modifications without direct confidentiality or availability consequences, attackers could leverage this flaw to alter site content, modify theme settings, or potentially chain with other vulnerabilities for more significant impact.

Root Cause

The root cause of this vulnerability lies in the Flatsome theme's failure to implement proper authorization checks on one or more AJAX handlers or theme functions. WordPress themes and plugins commonly expose endpoints that should verify user capabilities using functions like current_user_can() before executing privileged operations. The absence of these checks in the affected theme code allows unauthorized access to protected functionality.

Attack Vector

The attack can be executed remotely over the network by sending crafted HTTP requests to the vulnerable WordPress installation. Since no authentication is required and no user interaction is needed, an attacker can directly target exposed theme endpoints. The exploitation methodology involves identifying the vulnerable AJAX action or theme function and submitting requests that bypass the missing authorization controls.

The vulnerability affects the integrity of the target system, allowing attackers to make unauthorized modifications. However, it does not directly impact the confidentiality or availability of the affected systems based on the vulnerability characteristics.

Detection Methods for CVE-2026-31915

Indicators of Compromise

• Unexpected modifications to theme settings or site content without corresponding administrator activity logs
• Unusual POST requests to WordPress AJAX endpoints (/wp-admin/admin-ajax.php) from unauthenticated sources
• Unauthorized changes to Flatsome theme configurations or UX Builder elements

Detection Strategies

• Monitor WordPress access logs for suspicious AJAX requests targeting Flatsome-specific actions from unauthenticated users
• Implement Web Application Firewall (WAF) rules to detect and block unauthorized access attempts to theme endpoints
• Enable detailed WordPress logging to track administrative actions and identify unauthorized modifications

Monitoring Recommendations

• Review WordPress activity logs regularly for unauthorized theme configuration changes
• Deploy file integrity monitoring to detect unexpected modifications to theme files or database entries
• Monitor for unusual traffic patterns targeting WordPress admin-ajax.php endpoint

How to Mitigate CVE-2026-31915

Immediate Actions Required

• Update the Flatsome theme to a patched version beyond 3.19.6 as soon as one becomes available from UX-themes
• Review WordPress access logs to identify any potential exploitation attempts
• Implement Web Application Firewall rules to restrict access to WordPress AJAX endpoints from untrusted sources
• Consider temporarily restricting access to the WordPress admin area if exploitation is suspected

Patch Information

This vulnerability affects Flatsome theme versions through 3.19.6. Organizations should monitor the Patchstack Vulnerability Report for updates on available patches. Contact UX-themes directly for the latest security updates and upgrade to the newest available version that addresses this broken access control issue.

Workarounds

• Implement server-level access restrictions to limit exposure of WordPress AJAX endpoints to trusted IP ranges
• Use security plugins such as Wordfence or Sucuri to add additional access control layers and monitoring
• Deploy a Web Application Firewall (WAF) to filter and block potentially malicious requests targeting the vulnerable functionality
• Regularly audit WordPress user roles and capabilities to ensure principle of least privilege is enforced

# Example .htaccess rule to restrict admin-ajax.php access (adjust IP ranges as needed)
<Files admin-ajax.php>
    Order deny,allow
    Deny from all
    Allow from 192.168.1.0/24
    Allow from 10.0.0.0/8
</Files>