PT-2026-45681 · Pattihis · Simple Custom Login Page

Nguyen Duong · Published 2026-06-02 · Updated 2026-06-02 · CVE-2026-10100

Mitre

CVSS v3.1

4.4

Medium

Base vector

AV:N/AC:H/PR:H/UI:N/S:C/C:L/I:L/A:N

The Simple Custom Login Page plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the color settings fields (Page Background, Form Background, Text Color, Link Color) in versions up to and including 1.0.3. This is due to insufficient input sanitization of the color option values (they were registered with register setting() and stored via the Settings API/update option() with no sanitize callback) combined with the values being output into a block on wp-login.php using esc attr(), which is incorrect for a CSS context (it does not escape ;, {, }, / or *). This makes it possible for authenticated attackers, with administrator-level access and above, to inject arbitrary CSS rules into the login page that are rendered for all unauthenticated visitors, enabling UI-redress and credential-phishing attacks.

Fix

XSS

Weakness Enumeration

CWE-79

Related Identifiers

CVE-2026-10100

Affected Products

Simple Custom Login Page

References · 4

• https://nvd.nist.gov/vuln/detail/CVE-2026-10100 · Security Note
• https://wordfence.com/threat-intel/vulnerabilities/id/96d03984-623a-44c7-a46f-e1aabbc566d5?source=cve · Note
• https://plugins.trac.wordpress.org/browser/simple-custom-login-page/tags/1.0.3/admin/class-simple-custom-login-page-admin.php#L206 · Note
• https://plugins.trac.wordpress.org/browser/simple-custom-login-page/tags/1.0.3/includes/class-simple-custom-login-page.php#L248 · Note