CVE-2025-9877 is a stored Cross-Site Scripting (XSS) vulnerability identified in the Embed Google Datastudio plugin for WordPress, which is widely used to embed Google Data Studio reports within WordPress sites. The vulnerability exists due to improper neutralization of input during web page generation, specifically in the handling of the 'egds' shortcode attributes. All plugin versions up to and including 1.0.0 are affected. The root cause is insufficient input sanitization and lack of output escaping on user-supplied shortcode attributes, allowing authenticated users with contributor-level permissions or higher to inject arbitrary JavaScript code. When a page containing the injected shortcode is accessed by any user, the malicious script executes in their browser context. This can lead to session hijacking, privilege escalation, or unauthorized actions performed on behalf of the victim user. The vulnerability has a CVSS 3.1 base score of 6.4, reflecting a medium severity level with network attack vector, low attack complexity, privileges required (low), no user interaction, and a scope change. The impact affects confidentiality and integrity but not availability. No patches or official fixes are currently published, and no known exploits have been reported in the wild. The vulnerability was reserved and published in early September 2025 by Wordfence. Given the nature of WordPress plugins and their widespread use, this vulnerability poses a significant risk to websites using this plugin, especially those allowing contributor-level access to untrusted users.

The primary impact of CVE-2025-9877 is the potential for attackers with contributor-level access to inject persistent malicious scripts into WordPress pages, which execute in the browsers of any visitors to those pages. This can lead to theft of session cookies, enabling account takeover or privilege escalation, unauthorized actions performed on behalf of users, defacement of website content, or distribution of malware. Although availability is not directly affected, the integrity and confidentiality of user data and site content are at risk. Organizations relying on the Embed Google Datastudio plugin may face reputational damage, loss of user trust, and potential regulatory consequences if user data is compromised. The vulnerability's exploitation requires some level of authenticated access, which limits exposure but still poses a significant threat in environments where contributor roles are assigned to multiple users or where accounts may be compromised. The scope of affected systems includes all WordPress sites using the vulnerable plugin version, which could be substantial given the popularity of WordPress and Google Data Studio embedding. The absence of known exploits in the wild currently reduces immediate risk but does not eliminate the threat, especially as public disclosure may prompt attackers to develop exploits.

To mitigate CVE-2025-9877, organizations should first verify if they use the Embed Google Datastudio plugin and identify the installed version. Since no official patch is currently available, immediate mitigation includes restricting contributor-level access to trusted users only and auditing existing content for malicious shortcode injections. Implementing a Web Application Firewall (WAF) with rules to detect and block suspicious shortcode attribute patterns or script tags can help prevent exploitation. Site administrators should enforce the principle of least privilege, limiting the number of users with contributor or higher roles. Additionally, applying content security policies (CSP) that restrict inline scripts and untrusted sources can reduce the impact of injected scripts. Monitoring logs for unusual shortcode usage or unexpected content changes is recommended. Once a patch is released by the vendor, prompt updating of the plugin is critical. For longer-term security, consider using alternative plugins with better security track records or custom embedding solutions that sanitize inputs robustly.