Ultimate Member Plugin Allows Privilege Escalation via Role Validation Bypass

The Ultimate Member WordPress plugin before 2.13.0 does not validate a submitted role selection when it cannot resolve the set of roles a profile form permits, and screens the value against the site's registered role names rather than against the form's own allow-list, allowing unauthenticated users who register through the Ultimate Member WordPress plugin before 2.13.0's own form to grant themselves arbitrary capabilities and reach administrator-equivalent access.

Casky was already ahead

This CVE exploits attack patterns that Casky's 224matched skills already investigate — long before this vulnerability was disclosed. Claude's reasoning model maps these techniques to MITRE ATT&CK, so practitioners who ran these skills have already seen the threat behaviour in their findings.

Analysis

The Ultimate Member WordPress plugin before version 2.13.0 contains a critical privilege escalation vulnerability that allows unauthenticated users to grant themselves arbitrary capabilities and achieve administrator-equivalent access during registration. The flaw stems from improper input validation: when a profile form's role configuration cannot be resolved, the plugin fails to validate the submitted role against the form's own allowlist. Instead, it only screens the value against the site's registered role names—a significantly weaker control that permits attackers to select any role present in the WordPress installation, including admin. This vulnerability affects any WordPress site using the vulnerable plugin version with registration forms, creating a direct path for unauthorized privilege escalation that completely bypasses intended access controls.

Casky's 224 matching skills leverage Claude AI with extended reasoning to identify attack patterns aligned with MITRE ATT&CK TA0004 (Privilege Escalation). Practitioners using the platform would detect this vulnerability through skills that analyze: input validation bypasses in form processing logic, role/capability assignment without proper authorization checks, and authentication flows in user registration mechanisms. The platform's threat detection would flag suspicious indicators such as registration requests that assign unexpected role values, discrepancies between intended form role restrictions and actual granted permissions, and cases where unauthenticated users obtain elevated privileges. By correlating these patterns against MITRE ATT&CK techniques, Casky helps security teams recognize the characteristic signs of this privilege escalation chain—from initial unauthenticated registration through unauthorized capability assignment—enabling proactive detection before attackers achieve admin-level compromise.

Live Threat IntelligenceComing soon

Casky Risk Score

—

EPSS Probability

—

Shodan Exposure

—

GreyNoise Signal

—

Composite risk scoring from EPSS, CISA KEV, Shodan, and GreyNoise — 21 security APIs correlated into a single Casky Risk Score. Coming in Casky Pro. Join early access →

224 Casky skills cover this attack pattern

These skills use Claude AI's reasoning model to surface findings in the same attack categories as CVE-2026-19423.

abusing-dpapi-for-credential-access

red teaming · high

Run

abusing-shadow-credentials-for-privesc

red teaming · high

Run

Access with Stolen Session Cookie

identity access management · low

Run

MITRE ATT&CK Techniques

TA0004

Investigate the attack patterns behind CVE-2026-19423

Casky has 224 skills that investigate the attack patterns behind CVE-2026-19423. Run one and get CVSS-scored findings in 3 minutes.

Run the skill that detects this →

X Instagram LinkedIn