CVE-2025-11880 is a stored cross-site scripting vulnerability identified in the sierramike SM CountDown Widget plugin for WordPress, specifically in versions less than or equal to 1.2. The vulnerability arises from improper neutralization of input during web page generation (CWE-79), where the plugin fails to sufficiently sanitize and escape user-supplied attributes passed through the smcountdown shortcode. Authenticated attackers with contributor-level permissions or higher can exploit this flaw by injecting arbitrary JavaScript code into pages or posts. Because the malicious script is stored persistently, it executes in the context of any user who views the compromised page, potentially allowing attackers to hijack user sessions, steal cookies, perform actions on behalf of users, or deliver further malware. The vulnerability does not require user interaction beyond visiting the infected page and has a CVSS 3.1 base score of 6.4, reflecting medium severity with network attack vector, low attack complexity, and privileges required. The scope is changed (S:C) since the vulnerability affects resources beyond the attacker’s privileges. No public exploits or patches are currently available, increasing the urgency for mitigation. This vulnerability is particularly concerning for WordPress sites that allow contributor-level users to add or modify content, as it expands the attack surface beyond administrators. The plugin’s widespread use in content management and marketing sites increases the potential impact.

For European organizations, this vulnerability poses a significant risk to the confidentiality and integrity of web applications using the SM CountDown Widget plugin. Attackers with contributor access can inject malicious scripts that execute in the browsers of site visitors, including employees, customers, or partners, potentially leading to session hijacking, credential theft, unauthorized actions, or defacement. This can damage organizational reputation, lead to data breaches, and disrupt business operations. Since WordPress is widely used across Europe for corporate websites, e-commerce, and intranets, the vulnerability could affect a broad range of sectors including finance, healthcare, government, and retail. The medium severity score reflects that while the attack requires some privileges, the ease of exploitation and potential for persistent impact make it a credible threat. Additionally, the vulnerability’s ability to affect users beyond the attacker’s privilege level (scope changed) increases the risk of lateral impact within organizations. The lack of known exploits in the wild currently provides a window for proactive defense, but the presence of this vulnerability in a popular plugin demands immediate attention.

European organizations should take the following specific actions to mitigate this vulnerability: 1) Immediately audit WordPress sites to identify installations of the SM CountDown Widget plugin and determine the version in use. 2) Restrict contributor-level permissions to trusted users only and review user roles to minimize unnecessary privileges. 3) Until a patch is released, consider disabling or removing the vulnerable plugin to eliminate the attack vector. 4) Implement web application firewall (WAF) rules to detect and block suspicious shortcode inputs or script injections related to the smcountdown shortcode. 5) Employ Content Security Policy (CSP) headers to restrict the execution of unauthorized scripts on affected sites. 6) Educate content contributors about the risks of injecting untrusted content and enforce strict content review processes. 7) Monitor logs and site traffic for unusual activity that may indicate exploitation attempts. 8) Once a vendor patch is available, apply it promptly and verify the fix through testing. 9) Consider deploying security plugins that provide enhanced input sanitization and output encoding for WordPress shortcodes. These targeted measures go beyond generic advice by focusing on user role management, temporary plugin removal, and layered defenses specific to the vulnerability’s attack vector.