CVE-2026-13253 | THREATINT

Description

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.

PUBLISHED Reserved 2026-06-24 | Published 2026-07-09 | Updated 2026-07-09 | Assigner Wordfence

MEDIUM: 6.4CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:N