CVE-2025-9877 is a stored Cross-Site Scripting (XSS) vulnerability affecting the Embed Google Datastudio WordPress plugin developed by elangovan. The vulnerability exists in all versions up to and including 1.0.0 due to improper neutralization of user-supplied input within the 'egds' shortcode. Specifically, the plugin fails to adequately sanitize and escape attributes provided by users with contributor-level or higher privileges. This flaw allows an authenticated attacker to inject arbitrary JavaScript code into pages that utilize the vulnerable shortcode. When other users visit these pages, the malicious script executes in their browsers, potentially leading to session hijacking, privilege escalation, or unauthorized actions within the WordPress site context. The vulnerability requires authentication with at least contributor-level access but does not require user interaction to trigger once the malicious content is stored and viewed. The CVSS v3.1 base score is 6.4 (medium severity), reflecting network attack vector, low attack complexity, privileges required, no user interaction, and impact on confidentiality and integrity but not availability. No known exploits are reported in the wild as of the publication date (September 12, 2025). No patches or updates have been linked yet, indicating that mitigation may require manual intervention or disabling the plugin until a fix is released.

For European organizations, this vulnerability poses a moderate risk primarily to websites running WordPress with the Embed Google Datastudio plugin installed. The impact includes potential unauthorized disclosure of sensitive information (confidentiality impact) and modification of site content or user data (integrity impact). Attackers with contributor-level access—often internal users or compromised accounts—can leverage this flaw to escalate privileges or conduct further attacks such as phishing or malware distribution via injected scripts. This can damage organizational reputation, lead to data breaches, and disrupt business operations reliant on WordPress sites for communication or data visualization. Since the vulnerability does not affect availability directly, denial-of-service is less of a concern. However, the scope of impact depends on the extent of plugin usage and the sensitivity of the affected sites. European organizations with public-facing WordPress sites embedding Google Datastudio reports are at risk, especially those with multiple contributors or less stringent access controls. Compliance with GDPR and other data protection regulations may be impacted if personal data is exposed through the exploit.

1. Immediately audit WordPress sites for the presence of the Embed Google Datastudio plugin and identify versions up to 1.0.0. 2. Restrict contributor-level and higher user permissions to trusted personnel only, minimizing the risk of malicious input. 3. Until an official patch is released, consider disabling or uninstalling the plugin to eliminate the attack vector. 4. Implement Web Application Firewall (WAF) rules to detect and block suspicious shortcode attribute patterns or script injections related to the 'egds' shortcode. 5. Conduct regular security reviews of user-generated content and shortcodes to detect anomalous scripts or payloads. 6. Educate content contributors about safe input practices and the risks of injecting untrusted code. 7. Monitor logs for unusual activity related to shortcode usage or privilege escalations. 8. Once a patch is available, promptly update the plugin and verify that input sanitization and output escaping are properly enforced. 9. Employ Content Security Policy (CSP) headers to limit the impact of any injected scripts by restricting allowed script sources. These targeted measures go beyond generic advice by focusing on access control, plugin management, and proactive detection tailored to this specific vulnerability.