CVE-2026-108158 in plugNmeet-server
Summary
by MITRE • 10/09/2026
plugNmeet Server through 2.5.2 contains a path traversal vulnerability in the whiteboard conversion endpoint that allows any meeting participant to read server files via crafted filePath values. Attackers can supply ../ sequences so text or office documents are converted into page images, then fetch them unauthenticated through /download/uploadedFile/.
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Analysis
by VulDB Data Team • 10/09/2026
The plugNmeet Server software, specifically versions up to and including 2.5.2, contains a critical path traversal vulnerability within its whiteboard conversion endpoint. This security flaw arises from insufficient validation of user-supplied input regarding file paths during the process of converting text or office documents into page images for display in virtual meetings. The vulnerability allows any authenticated meeting participant to manipulate the filePath parameter by injecting directory traversal sequences, such as ../, which bypass intended access controls and enable unauthorized reading of arbitrary files on the server's filesystem. This issue is classified under CWE-22: Improper Limitation of a Pathname to a Restricted Directory, indicating that the application fails to properly sanitize or restrict file path inputs before processing them.
From an operational perspective, this vulnerability poses significant risks to data confidentiality and integrity within collaborative environments utilizing plugNmeet. An attacker who is part of a meeting can exploit this flaw to access sensitive server files that are not intended for public viewing or participant access. By crafting specific filePath values containing traversal sequences, the attacker forces the server to resolve paths outside the designated upload directory. Once these external files are processed into image formats through the conversion mechanism, they become accessible via an unauthenticated endpoint at /download/uploadedFile/. This means that even users who do not have direct administrative privileges can retrieve confidential documents, configuration files, or other sensitive data stored on the server, leading to potential information disclosure and compromise of organizational security.
The exploitation chain relies on the interaction between two components: the whiteboard conversion service and the file download endpoint. The attacker first submits a malicious request to the conversion endpoint with a crafted filePath argument that includes ../ sequences pointing to target files located in restricted directories. After the server processes this request and generates image representations of the accessed content, the attacker subsequently requests these generated images through the /download/uploadedFile/ route. Because this download endpoint does not enforce authentication or verify the origin of the requested file beyond its presence in a temporary storage area, it serves as an effective vector for exfiltrating data without requiring elevated privileges. This behavior aligns with ATT&CK technique T1083: File and Directory Discovery, where adversaries explore local systems to gather information necessary for further attacks or lateral movement.
Mitigation strategies must focus on both immediate remediation and long-term architectural improvements. The most effective solution is to upgrade plugNmeet Server to a version newer than 2.5.2, assuming the vendor has released patches addressing this specific path traversal issue. In cases where upgrading is not immediately feasible, administrators should implement strict input validation mechanisms that reject any filePath values containing directory traversal characters such as ../ or ..\ regardless of encoding attempts. Additionally, implementing allowlists for permitted file extensions and restricting access to sensitive directories at the application level can reduce exposure. Web Application Firewalls (WAFs) may also be configured to detect and block requests with suspicious path patterns targeting restricted areas of the filesystem. Regular security audits and penetration testing should be conducted to identify similar vulnerabilities in other endpoints that handle user-controlled file paths, ensuring comprehensive protection against information disclosure attacks.