Stored Cross-Site Scripting in Ultimate Member Plugin by WordPress
CVE-2026-18547

6.4MEDIUM

Key Information:

Vendor

WordPress
Status
Ultimate Member – User Profile, Registration, Login, Member Directory, Content Restriction & Membership Plugin
Vendor
CVE Published:
25 August 2026

What is CVE-2026-18547?

The Ultimate Member plugin for WordPress, through its Textarea Profile Field with HTML Support, is susceptible to Stored Cross-Site Scripting vulnerabilities. This issue arises from inadequate input sanitization and output escaping, allowing authenticated users with subscriber-level access and higher to inject arbitrary web scripts. These scripts execute whenever a user loads the affected page, as the wp_kses 'templates' allowlist incorrectly permits the id attribute on div elements while failing to neutralize unescaped quotes. Consequently, when profile pages are rendered, the improper concatenation of these values enables JavaScript execution, posing a significant security risk.

Affected Version(s)

Ultimate Member – User Profile, Registration, Login, Member Directory, Content Restriction & Membership Plugin 0 <= 2.12.1

References

https://www.wordfence.com/threat-intel/vulnerabilities/id...
https://plugins.trac.wordpress.org/browser/ultimate-membe...
https://plugins.trac.wordpress.org/browser/ultimate-membe...

CVSS V3.1

Score:
6.4
Severity:
MEDIUM
Confidentiality:
Low
Integrity:
Low
Availability:
Low
Attack Vector:
Network
Attack Complexity:
Low
Privileges Required:
Low
User Interaction:
None
Scope:
Changed

Timeline

  • Vulnerability published

  • Vulnerability Reserved

Credit

tiborisaak
.