CVE-2025-11518 is an authorization bypass vulnerability classified under CWE-639 (Authorization Bypass Through User-Controlled Key) found in the WPC Smart Wishlist for WooCommerce plugin for WordPress. This plugin enables users to create and share wishlists on WooCommerce-powered e-commerce sites. The vulnerability arises from insecure direct object references (IDOR) in several AJAX functions related to wishlist management. Specifically, the plugin exposes a user-controlled key when wishlists are shared, but fails to validate this key properly on the server side. As a result, an unauthenticated attacker who obtains this key can manipulate other users' wishlists by adding or removing items without authorization. The vulnerability affects all versions up to and including 5.0.3. The CVSS 3.1 base score is 5.3 (medium severity), reflecting that the attack vector is network-based (AV:N), requires no privileges (PR:N), no user interaction (UI:N), and impacts integrity (I:L) but not confidentiality or availability. No known exploits have been reported in the wild to date. The lack of authentication requirements and the exposure of the key in shared wishlists increase the risk of exploitation, especially on sites where wishlist sharing is common. The vulnerability could be leveraged to disrupt user experience, damage trust, or facilitate further social engineering attacks by manipulating wishlist contents. The plugin vendor has not yet published a patch, so users must apply mitigations proactively.

For European organizations operating WooCommerce-based e-commerce platforms, this vulnerability poses a risk to the integrity of customer data, specifically wishlist contents. While it does not expose sensitive personal information or disrupt service availability, unauthorized modification of wishlists can degrade user trust and satisfaction, potentially impacting sales and brand reputation. Attackers could exploit this flaw to remove desirable items or insert misleading products, which may confuse customers or interfere with marketing campaigns. In sectors where wishlists are used for gift registries or event planning, such manipulation could have more pronounced negative effects. The vulnerability's ease of exploitation without authentication increases the threat surface, especially for popular online stores with active wishlist sharing. Although no direct financial theft or data breach is indicated, the indirect consequences on customer relations and operational integrity could be significant. Organizations in Europe with high WooCommerce usage should prioritize addressing this issue to maintain competitive e-commerce service quality.

European organizations should implement the following specific mitigations: 1) Immediately audit the usage of the WPC Smart Wishlist plugin and identify all instances and versions in use. 2) Disable wishlist sharing features temporarily if feasible to prevent exposure of user-controlled keys. 3) Implement server-side validation to ensure that any wishlist modification requests are authorized and correspond to the authenticated user or valid session context. 4) Monitor web server logs for unusual AJAX requests targeting wishlist functions, especially those originating from unauthenticated sources. 5) Educate development teams to review and sanitize all user-controlled inputs related to wishlist keys. 6) Engage with the plugin vendor or community to obtain or contribute to a security patch; apply updates promptly once available. 7) Consider deploying Web Application Firewalls (WAF) with custom rules to detect and block suspicious wishlist manipulation attempts. 8) Communicate transparently with customers if any manipulation is detected to maintain trust. These steps go beyond generic advice by focusing on access control, input validation, monitoring, and proactive risk reduction tailored to this specific vulnerability.