CVE-2025-27006 is a Stored Cross-Site Scripting (XSS) vulnerability classified under CWE-79, affecting the Authorsy product developed by themeplugs, specifically versions up to 1.0.5. Stored XSS occurs when malicious input is improperly neutralized and subsequently stored by the web application, later served to users without adequate sanitization or encoding. This vulnerability enables an attacker with at least low privileges (PR:L) and requiring user interaction (UI:R) to inject malicious scripts into web pages generated by Authorsy. The vulnerability has a CVSS v3.1 base score of 6.5, indicating a medium severity level. The vector string (AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:L) reveals that the attack can be performed remotely over the network with low attack complexity, requires some level of authentication, and user interaction is necessary to trigger the exploit. The scope is changed (S:C), meaning the vulnerability affects resources beyond the initially vulnerable component. The impact affects confidentiality, integrity, and availability at a low level, as the injected scripts could steal user data, manipulate content, or disrupt service. No public exploits are currently known in the wild, and no patches have been linked yet. The vulnerability arises from improper input neutralization during web page generation, a common issue in web applications that do not properly sanitize or encode user-supplied data before rendering it in HTML contexts.

For European organizations using the Authorsy platform, this vulnerability poses a risk of client-side attacks that can lead to session hijacking, credential theft, unauthorized actions on behalf of users, and potential defacement or misinformation through manipulated content. Since Authorsy is a web-based product, any organization relying on it for content management or user interaction could see compromised user trust and data confidentiality breaches. The medium severity and requirement for user interaction mean that phishing or social engineering could be leveraged to exploit this vulnerability. The scope change implies that the impact could extend beyond the immediate application, potentially affecting integrated systems or services. This could be particularly damaging for sectors with strict data protection regulations such as finance, healthcare, and government institutions in Europe, where data breaches can lead to significant legal and reputational consequences under GDPR. Additionally, the vulnerability could be exploited to deliver malware or conduct further attacks within the network if the malicious scripts gain sufficient privileges.

European organizations should prioritize the following specific mitigation steps: 1) Immediately audit all instances of Authorsy in use to identify affected versions (up to 1.0.5) and plan for an upgrade or patch application as soon as a fix is released by themeplugs. 2) Implement robust input validation and output encoding on all user-supplied data within the application, especially in areas where content is stored and later rendered. 3) Employ Content Security Policy (CSP) headers to restrict the execution of unauthorized scripts and reduce the impact of potential XSS payloads. 4) Conduct regular security testing, including automated scanning and manual penetration testing focused on XSS vulnerabilities, to detect similar issues proactively. 5) Educate users and administrators about the risks of phishing and social engineering attacks that could trigger stored XSS exploits. 6) Monitor web application logs and user activity for unusual behavior indicative of exploitation attempts. 7) Isolate the Authorsy application environment where possible to limit lateral movement in case of compromise. 8) Engage with themeplugs or the security community for updates on patches or workarounds and apply them promptly once available.