CVE-2025-49585 is a high-severity vulnerability affecting multiple versions of the XWiki platform, a widely used generic wiki software. The vulnerability arises from insufficient user interface warnings regarding dangerous operations, specifically when creating and editing XClass definitions. In affected versions prior to 15.10.16, between 16.0.0-rc-1 and 16.4.6, and between 16.5.0-rc-1 and 16.10.1, an attacker with edit rights but without script or programming rights can create an XClass definition containing malicious code. When a user with elevated privileges (script, admin, or programming rights) subsequently edits the same document, the malicious code embedded in custom display code, computed properties scripts, or database list property queries can execute with the elevated user's privileges. This execution occurs without any prior warning to the privileged user, due to insufficient UI notifications about the potential danger of the operation. The vulnerability is categorized under CWE-357, which concerns insufficient UI warnings of dangerous operations. The issue was partially addressed by introducing warnings starting in version 15.9, but the full fix was implemented in versions 15.10.16, 16.4.7, and 16.10.2 by adding property analysis to detect and prevent execution of malicious code embedded in XClass properties. The CVSS 4.0 score of 8.6 reflects a high severity, with network attack vector, low attack complexity, no required privileges beyond edit rights, and user interaction required (the privileged user must edit the document). The impact on confidentiality, integrity, and availability is high due to the potential for arbitrary code execution with elevated privileges. No known exploits are currently reported in the wild, but the vulnerability presents a significant risk if weaponized.

For European organizations using affected versions of XWiki, this vulnerability poses a substantial risk. Attackers with limited privileges can craft malicious XClass definitions that, when edited by administrators or users with scripting rights, lead to arbitrary code execution with elevated privileges. This can result in unauthorized access to sensitive data, modification or deletion of critical content, and potential disruption of wiki services. Given that XWiki is often used for internal documentation, knowledge management, and collaboration, compromise could lead to leakage of proprietary information or intellectual property. Additionally, the elevated code execution could serve as a foothold for lateral movement within enterprise networks. The lack of prior warning increases the likelihood that privileged users may inadvertently trigger the exploit. The impact is particularly critical in sectors where XWiki is integrated into business-critical workflows or regulatory compliance documentation, such as finance, healthcare, and government agencies across Europe.

1. Immediate upgrade to patched versions: Organizations should upgrade to XWiki versions 15.10.16, 16.4.7, or 16.10.2 or later, where the vulnerability is fully addressed. 2. Restrict edit rights: Limit the ability to create or modify XClass definitions to the smallest necessary group of trusted users to reduce the attack surface. 3. Implement strict role-based access controls (RBAC): Ensure that users with script, admin, or programming rights are carefully vetted and monitored. 4. Enable and enforce UI warnings: For versions supporting warnings (15.9 and later), ensure that these features are enabled and that users are trained to heed warnings about dangerous operations. 5. Conduct regular audits: Review XClass definitions and documents with computed properties or custom display code for suspicious or unauthorized changes. 6. Monitor logs and user activity: Implement monitoring to detect unusual editing patterns or privilege escalations related to XWiki documents. 7. Network segmentation: Isolate XWiki servers to limit potential lateral movement if compromise occurs. 8. Incident response preparedness: Develop and test response plans specific to wiki platform compromises, including backup and recovery procedures for wiki content.