CVE-2025-57979 is a medium-severity Stored Cross-Site Scripting (XSS) vulnerability affecting the AuthorSure product developed by Russell Jamieson, specifically versions up to 2.3. The vulnerability arises from improper neutralization of input during web page generation, classified under CWE-79. Stored XSS occurs when malicious input is saved by the application and later rendered in web pages without proper sanitization or encoding, allowing attackers to execute arbitrary JavaScript code in the context of other users' browsers. This can lead to session hijacking, defacement, or redirection to malicious sites. The CVSS 3.1 vector indicates the attack can be performed remotely over the network (AV:N) with low attack complexity (AC:L), but requires high privileges (PR:H) and user interaction (UI:R). The scope is changed (S:C), meaning the vulnerability affects resources beyond the initially vulnerable component. The impact includes low confidentiality, integrity, and availability impacts, reflecting limited data exposure or modification potential. No known exploits are currently reported in the wild, and no patches have been linked yet. The vulnerability was published on September 22, 2025, with the CVE reserved a month earlier. AuthorSure is a content management or authoring tool, and the vulnerability likely affects web applications relying on it for content generation.

For European organizations using AuthorSure, this vulnerability poses a risk of persistent XSS attacks that could compromise user sessions, steal credentials, or manipulate displayed content. Although the impact on confidentiality, integrity, and availability is rated low to medium, the exploitation requires high privileges and user interaction, which somewhat limits the attack surface. However, in environments where AuthorSure is used to manage sensitive or high-traffic web content, successful exploitation could lead to reputational damage, loss of user trust, and potential regulatory scrutiny under GDPR if personal data is exposed or manipulated. The cross-site scripting could also be leveraged as a foothold for further attacks within the network, especially if combined with social engineering. Given the lack of known exploits, the immediate risk is moderate, but organizations should not underestimate the potential for targeted attacks, especially in sectors like publishing, education, or government where AuthorSure might be deployed.

Organizations should immediately audit their use of AuthorSure to identify affected versions (up to 2.3) and plan for an upgrade or patch once available. In the absence of official patches, implement web application firewall (WAF) rules to detect and block suspicious input patterns that could trigger stored XSS. Employ strict Content Security Policy (CSP) headers to restrict execution of unauthorized scripts. Conduct thorough input validation and output encoding on all user-supplied data rendered in web pages, using context-aware encoding libraries. Limit the privileges of users who can submit content to reduce the risk posed by high-privilege requirements. Monitor logs for unusual activity indicative of XSS exploitation attempts. Additionally, educate users about the risks of interacting with suspicious content and ensure that multi-factor authentication is enforced to mitigate session hijacking risks. Finally, maintain an incident response plan tailored to web application attacks to respond swiftly if exploitation is detected.