CVE Catalog

CVE-2026-13253

MediumCVSS 6.4
Published: Updated: Translated: NVD NIST

Exploitation Probability (EPSS)

Low risk
0.21%

11th percentile - higher than 11% of all known CVEs

Summary

The Ultimate Post plugin for WordPress up to version 5.0.31 is vulnerable to Stored Cross-Site Scripting. Attackers with contributor-level access or higher can inject malicious JavaScript via the 'moreResultsText' attribute of the advanced search block due to insufficient input sanitization and output escaping.

Risk Assessment

The risk involves arbitrary script execution in the victim's browser, potentially leading to session theft, redirects to malicious sites, or theft of sensitive data. The vulnerability can be exploited by users with limited privileges, increasing its reach.

Recommendation

Immediately update the Ultimate Post plugin to the latest available version that fixes this vulnerability. Additionally, restrict user permissions to the minimum necessary and regularly review content published by contributors.

Related vulnerabilities

Original NVD description (English source)

The Ultimate Post plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the 'moreResultsText' block attribute of the ultimate-post/advanced-search block in versions up to and including 5.0.31. This is due to insufficient input sanitization and output escaping in the Advanced_Search::content() render callback: the attribute value is filtered with wp_kses(), which strips disallowed HTML tags but does NOT escape HTML special characters such as double quotes in plain text, and the result is then concatenated directly into the data-viewmoretext HTML attribute without esc_attr(). This makes it possible for authenticated attackers, with contributor-level access and above, to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page.

Vulnerability data from NVD (NIST) · CISA KEV · EPSS