CVE-2025-40706 is a Cross-Site Scripting (XSS) vulnerability identified in version 8.9.0 of OpenAtlas, a software product developed by the Austrian Centre for Digital Humanities and Cultural Heritage (ACDH-CH). The vulnerability arises from improper neutralization of user input during web page generation, specifically in the handling of the "name" parameter within POST requests sent to the "/insert/source" endpoint. Due to insufficient input validation and sanitization, an attacker can craft malicious queries that, when processed by an authenticated user’s browser, execute arbitrary scripts. This can lead to the theft of session cookies and potentially other sensitive information, enabling session hijacking or impersonation of the authenticated user. The vulnerability requires the attacker to send a specially crafted POST request and relies on user interaction (the victim must be authenticated and access the malicious payload). The CVSS 4.0 base score is 5.1 (medium severity), reflecting that the attack vector is network-based with low attack complexity, no privileges required, but user interaction is necessary. The vulnerability does not impact confidentiality, integrity, or availability directly beyond session cookie theft and potential unauthorized actions performed under the hijacked session. There are no known exploits in the wild at the time of publication, and no patches have been released yet. The vulnerability is classified under CWE-79, which covers improper neutralization of input leading to XSS attacks.

For European organizations using OpenAtlas 8.9.0, particularly those in the digital humanities, cultural heritage, and academic sectors, this vulnerability poses a risk of session hijacking and unauthorized access to user accounts. Attackers could exploit this flaw to impersonate legitimate users, potentially gaining access to sensitive research data, user information, or administrative functions within the platform. This could lead to data breaches, unauthorized data manipulation, or disruption of services. Since OpenAtlas is used for managing digital humanities data, the compromise could also affect the integrity and confidentiality of cultural heritage information. The medium severity score indicates a moderate risk; however, the impact could be more significant if privileged accounts are compromised. Additionally, the requirement for user interaction and authentication limits the attack scope but does not eliminate risk, especially in environments where users may be targeted via phishing or social engineering. The lack of known exploits currently suggests a window for proactive mitigation before widespread exploitation occurs.

1. Immediate mitigation should focus on restricting access to the "/insert/source" endpoint to trusted users and networks, minimizing exposure to untrusted sources. 2. Implement strict input validation and output encoding on the "name" parameter to neutralize any potentially malicious scripts. This includes using established libraries or frameworks that automatically handle XSS prevention. 3. Employ Content Security Policy (CSP) headers to restrict the execution of unauthorized scripts in the browser context. 4. Educate users about phishing and social engineering risks to reduce the likelihood of them interacting with malicious payloads. 5. Monitor web server logs for suspicious POST requests to the vulnerable endpoint and unusual user activity that could indicate exploitation attempts. 6. Since no patch is currently available, consider deploying Web Application Firewalls (WAFs) with custom rules to detect and block malicious payloads targeting this vulnerability. 7. Plan for prompt application of official patches or updates from ACDH-CH once released. 8. Review and enforce secure session management practices, such as using HttpOnly and Secure flags on cookies, to limit the impact of session theft.