CVE-2025-68935 in Document Server
Summary
by MITRE • 12/25/2025
ONLYOFFICE Docs before 9.2.1 allows XSS via the Font field for the Multilevel list settings window. This is related to DocumentServer.
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Analysis
by VulDB Data Team • 01/03/2026
The vulnerability identified as CVE-2025-68935 represents a cross-site scripting weakness in ONLYOFFICE Docs versions prior to 9.2.1, specifically affecting the Multilevel list settings window functionality. This issue resides within the DocumentServer component of the software ecosystem, which serves as the core backend processing engine for document manipulation and rendering. The vulnerability manifests when users interact with the font field configuration options within the multilevel list settings interface, creating an attack surface that could be exploited by malicious actors to inject malicious scripts into the application's rendering environment.
The technical flaw stems from inadequate input validation and sanitization of user-supplied data within the font field parameter processing. When users enter font names or font-related configurations in the multilevel list settings window, the application fails to properly escape or filter special characters that could be interpreted as executable script code. This deficiency allows attackers to craft malicious payloads that, when processed by the DocumentServer, execute within the context of the victim's browser session. The vulnerability specifically targets the rendering pipeline of document elements where font configurations are applied to multilevel lists, making it particularly dangerous in collaborative document environments where multiple users may interact with the same document.
The operational impact of this vulnerability extends beyond simple script execution, as it can enable attackers to perform session hijacking, steal sensitive user information, or redirect victims to malicious websites. In enterprise environments where ONLYOFFICE Docs is used for document collaboration and management, this vulnerability could be exploited to gain unauthorized access to confidential business documents or compromise user credentials. The attack requires minimal privileges and can be executed through normal user interaction with the document editing interface, making it particularly concerning for organizations that rely heavily on document collaboration features. The vulnerability's location within the DocumentServer component means that it affects all applications and services that depend on this backend processing engine, potentially creating widespread impact across integrated systems.
Mitigation strategies should focus on immediate patching of the software to version 9.2.1 or later, which includes proper input validation and output encoding mechanisms. Organizations should also implement additional security measures such as content security policy headers to prevent unauthorized script execution, regular security scanning of document upload functionalities, and user education about avoiding suspicious document attachments. From a compliance perspective, this vulnerability aligns with CWE-79 Cross-site Scripting and addresses ATT&CK technique T1566 Phishing, as attackers could leverage this vulnerability to deliver malicious payloads through compromised documents. Network segmentation and web application firewalls can provide additional defense-in-depth layers, while regular vulnerability assessments should be conducted to identify similar input validation weaknesses in other document processing components. The remediation process should also include thorough testing of the patched version to ensure that legitimate document functionality remains intact while addressing the XSS vulnerability.