YesWiki before 4.6.7 contains a server‑side request forgery vulnerability that allows page editors to make the server fetch arbitrary URLs via the url parameter of the Bazar valeur action. Attackers can embed the action with a champ parameter in wiki markup to reach loopback or internal services and partially read responses rendered into the page. This moderate impact is reflected by a CVSS score of 5.3.

All installations of YesWiki running a version earlier than 4.6.7 are affected. The product is YesWiki, developed by the YesWiki community, and the vulnerability resides in the Bazar module of that product.

The exploit requires authenticated page‑editor access to supply the malicious URL. Once executed, the attacker can probe internal networks and read responses rendered into the page. The CVSS score of 5.3 reflects moderate impact; the EPSS score is < 1%, and the vulnerability is not listed in the CISA KEV catalog, indicating that while exploitable, it is not currently known to be actively used in widespread attacks.