Executive brief
YesWiki, a PHP-based wiki system, contains a security flaw that allows attackers to inject malicious scripts into form titles. Because these scripts are saved in the database, they automatically run in the browser of any user who views the affected page. This could lead to unauthorized actions being performed on behalf of users, including administrators, or the theft of sensitive session information.
Technical details
A stored and blind Cross-Site Scripting (XSS) vulnerability exists in YesWiki prior to version 4.6.0. The root cause is improper neutralization of user-controllable input in the form title field (specifically within the BazaR component). An unauthenticated attacker can submit a malicious JavaScript payload via the 'Name of the event' or 'Description' fields when creating a record. This payload is stored in the backend database and executed whenever a user, including those with administrative privileges, visits the page displaying the record (e.g., via the 'consulter' view). This can lead to session hijacking or unauthorized data access. The issue is addressed in version 4.6.0.
Affected products
- YesWiki YesWiki < 4.6.0
Timeline
- 2026-03-20: patched: Version 4.6.0 released.
- 2026-03-29: advisory: GitHub Security Advisory published.
- 2026-04-02: disclosed: CVE published to NVD.