CVE-2026-26000 in xwiki-platform
Summary
by MITRE • 02/12/2026
XWiki Platform is a generic wiki platform offering runtime services for applications built on top of it. Prior to 17.9.0, 17.4.6, and 16.10.13, it's possible using comments to inject CSS that would transform the full wiki in a link area leading to a malicious page. This vulnerability is fixed in 17.9.0, 17.4.6, and 16.10.13.
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Analysis
by VulDB Data Team • 02/20/2026
The vulnerability identified as CVE-2026-26000 affects the XWiki Platform, a widely used generic wiki platform that provides runtime services for applications built upon it. This platform serves as a foundation for numerous collaborative environments and content management systems, making its security critical for organizations relying on wiki-based workflows. The vulnerability represents a significant concern as it allows attackers to manipulate the platform's user interface through comment functionality, potentially redirecting users to malicious websites without their knowledge.
The technical flaw manifests through improper input validation and sanitization within the comment processing mechanism of the XWiki Platform. Attackers can exploit this weakness by submitting carefully crafted CSS code through comments that gets rendered within the wiki interface. This malicious CSS injection transforms the entire wiki page into a link area, effectively creating a phishing vector that can redirect users to attacker-controlled domains. The vulnerability specifically targets the rendering engine's handling of user-generated content, particularly comments, where CSS styles are not adequately sanitized before being displayed to end users.
The operational impact of this vulnerability extends beyond simple phishing attacks, as it fundamentally compromises the integrity and trustworthiness of the wiki platform itself. When users interact with the compromised wiki, they may unknowingly navigate to malicious sites that could attempt to steal credentials, install malware, or conduct further social engineering attacks. The vulnerability affects multiple versions of the platform, specifically those prior to 17.9.0, 17.4.6, and 16.10.13, indicating it was a persistent issue that required multiple version updates to address. Organizations using affected versions face significant risk as the attack can be executed without requiring elevated privileges or complex exploitation techniques.
This vulnerability aligns with CWE-79, which describes Cross-Site Scripting (XSS) conditions where improperly sanitized user-provided data is executed in the browser. The specific implementation weakness falls under the category of reflected XSS, though in this case it's more accurately characterized as a stored XSS variant since the malicious CSS persists in the comment system. The attack pattern corresponds to techniques described in the MITRE ATT&CK framework under T1566, specifically targeting credential harvesting and phishing through web-based attacks. The vulnerability demonstrates how seemingly innocuous features like comment systems can become attack vectors when proper input validation is not implemented.
The recommended mitigation strategy involves immediate deployment of the patched versions 17.9.0, 17.4.6, and 16.10.13, depending on the organization's current platform version. Administrators should also implement additional security measures including comprehensive input validation for all user-generated content, particularly CSS and HTML elements, and regular security audits of comment and content management systems. Organizations should consider implementing Content Security Policy (CSP) headers to further restrict script execution and prevent unauthorized CSS injection. The fix addresses the root cause by implementing proper sanitization of user-provided CSS content before rendering, ensuring that malicious code cannot be executed within the wiki interface.