CVE-2026-0557 identifies a stored cross-site scripting (XSS) vulnerability in the WP Data Access plugin for WordPress, a no-code app builder that enables creation of tables, forms, charts, and maps. The vulnerability exists in the 'wpda_app' shortcode, which fails to properly sanitize and escape user-supplied attributes before rendering them on web pages. This improper neutralization of input (CWE-79) allows authenticated users with contributor-level permissions or higher to inject arbitrary JavaScript code into pages. When other users visit these pages, the malicious scripts execute in their browsers, potentially compromising session tokens, cookies, or enabling unauthorized actions. The vulnerability affects all plugin versions up to and including 5.5.63. The CVSS v3.1 base score is 6.4, reflecting a medium severity with network attack vector, low attack complexity, requiring privileges (contributor or above), no user interaction, and impacting confidentiality and integrity with a scope change. No public exploits are known at this time, but the vulnerability's presence in a popular WordPress plugin poses a significant risk. The flaw's exploitation could facilitate persistent XSS attacks that persist across sessions and users, making it a serious concern for website administrators. The lack of an official patch at the time of reporting necessitates immediate mitigation efforts to reduce risk.

The exploitation of this stored XSS vulnerability can have several impacts on affected organizations. Attackers with contributor-level access can inject malicious scripts that execute in the context of other users, including administrators, potentially leading to session hijacking, theft of sensitive information, or unauthorized actions such as content manipulation or privilege escalation. This can undermine the integrity and confidentiality of the website and its users. Additionally, persistent XSS can be leveraged to deploy further attacks like phishing or malware distribution. For organizations relying on the WP Data Access plugin, this vulnerability could lead to reputational damage, loss of user trust, and compliance issues if sensitive data is compromised. Since WordPress powers a significant portion of the web, and this plugin is used globally, the scope of impact is broad. The requirement for authenticated access limits exploitation to insiders or compromised accounts, but the low attack complexity and no need for user interaction increase the risk. Overall, the vulnerability poses a medium risk but could be escalated if combined with other vulnerabilities or social engineering tactics.

To mitigate this vulnerability, organizations should immediately restrict contributor-level access to trusted users only, minimizing the risk of malicious input injection. Administrators should audit existing content generated via the 'wpda_app' shortcode for suspicious scripts and remove any unauthorized code. Until an official patch is released, implementing web application firewall (WAF) rules to detect and block malicious payloads targeting the shortcode parameters can reduce exploitation risk. Employing Content Security Policy (CSP) headers can help limit the impact of injected scripts by restricting the sources of executable scripts. Regularly updating WordPress and all plugins, including WP Data Access, as soon as patches become available is critical. Additionally, security teams should monitor logs for unusual activity from contributor accounts and educate users about the risks of privilege misuse. Developers maintaining the plugin should prioritize releasing a patch that properly sanitizes and escapes all user inputs in the shortcode. Finally, consider disabling or replacing the plugin if immediate patching is not feasible.