CVE-2026-93428 ultimatemember CVE debrief

Who should care

Defenders responsible for WordPress installations with the Ultimate Member plugin should assess exposure and implement compensating controls to prevent unauthorized access to sensitive member profile information.

Why it matters

The Ultimate Member plugin vulnerability allows unauthorized access to member profile field values, potentially leading to data exposure. Defenders should verify exposure, implement compensating controls, and prioritize patching or workarounds.

• Potential unauthorized access to sensitive member profile information
• Possible data exposure due to improper authorization verification
• Need for compensating controls to restrict access to sensitive member profile fields
• Verification of exposure and implementation of patches or workarounds is required

Technical summary

The Ultimate Member plugin for WordPress is vulnerable to authorization bypass due to improper verification of user authorization. This allows unauthenticated attackers to view privacy-restricted member profile field values by querying the publicly accessible wp_ajax_nopriv_um_get_members endpoint. The nonce 'um-frontend-nonce' is publicly accessible and does not provide meaningful access control. The vulnerability is due to inadequate authorization checks in the plugin's code. Defenders should prioritize verifying exposure and implementing compensating controls to restrict access to sensitive member profile information.

Defensive priority

Defenders should prioritize verifying exposure and implementing compensating controls, as the vulnerability allows unauthorized access to sensitive member profile information.

Recommended defensive actions

• Verify exposure by checking if the Ultimate Member plugin version is 2.13.1 or earlier
• Implement compensating controls, such as restricting access to sensitive member profile fields
• Monitor for suspicious activity on the wp_ajax_nopriv_um_get_members endpoint
• Consider upgrading to a patched version of the Ultimate Member plugin
• Review and update access controls for member profile fields
• Conduct regular security audits to identify potential vulnerabilities
• Implement additional logging and monitoring to detect potential exploitation attempts

Evidence notes

The vulnerability is due to improper authorization verification in the Ultimate Member plugin, specifically in the wp_ajax_nopriv_um_get_members endpoint. The nonce 'um-frontend-nonce' is publicly accessible and does not provide meaningful access control.

Sources and references

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.