Vulnerability · Published Jun 2, 2026 · Assigned by Wordfence

CVE-2026-10100Simple Custom Login Page <= 1.0.3 - Authenticated (Admin+) Stored Cross-Site Scripting

Medium 4.4

In plain English

A medium-severity cross-site scripting in Simple Custom Login Page from pattihis. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.2% (higher than 8% of all known vulnerabilities).

Severity (CVSS 3.1)4.4Medium
Exploit odds (30 days)0.2%top 92.0% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack toolingNoneno public tooling known

Official description

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 <style> 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.

Affected products (as reported)

VendorProductVersions
pattihis Simple Custom Login Page 0 – through 1.0.3

Weakness: CWE-79 · Vector: CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:C/C:L/I:L/A:N

References