CVE-2026-103481: Gwolle Guestbook <= 5.1.1 - Reflected Cross-Site Scripting via 'permalink' Parameter
The Gwolle Guestbook plugin for WordPress is vulnerable to Reflected Cross-Site Scripting via the 'permalink' parameter in all versions up to, and including, 5.1.1 due to insufficient input sanitization and output escaping. This makes it possible for unauthenticated attackers to inject arbitrary web scripts in pages that execute if they can successfully trick a user into performing an action such as clicking on a link.
Affected Software
Event History
Frequently Asked Questions
Who can exploit this issue, and what interaction is required?
An unauthenticated attacker can attempt exploitation remotely. Successful script execution requires convincing a user to perform an action such as clicking a crafted link containing the malicious permalink parameter.
Which installations are affected?
Gwolle Guestbook versions up to and including 5.1.1 are affected. The provided information does not identify any configuration prerequisite, so installations running an affected version should be treated as exposed where users can reach the vulnerable page.
What could happen if exploitation succeeds?
Malicious script can execute in the affected user's browser in the context of the vulnerable site. The reported impact includes low confidentiality and integrity impact, while availability is not affected.