CVE-2025-65838 identifies a path traversal vulnerability in PublicCMS version V5.202506.b, specifically within the doUploadSitefile method. Path traversal (CWE-22) vulnerabilities occur when an application improperly sanitizes user-supplied input, allowing attackers to manipulate file paths to access files outside the intended directory. In this case, an unauthenticated attacker can remotely send crafted requests to the doUploadSitefile method, exploiting insufficient input validation to traverse directories and read arbitrary files on the server. The vulnerability affects confidentiality by exposing sensitive files but does not impact integrity or availability, as the attacker cannot modify or delete files or disrupt service. The CVSS 3.1 score of 7.5 reflects the ease of exploitation (network vector, no privileges or user interaction required) and the high confidentiality impact. Although no known exploits are currently reported in the wild and no patches have been published, the vulnerability's presence in a web content management system widely used for website hosting and content delivery poses a significant risk. Attackers could leverage this flaw to access configuration files, credentials, or other sensitive data, potentially leading to further compromise. The lack of affected version details beyond V5.202506.b suggests the need for organizations to verify their deployment versions. The vulnerability was reserved on 2025-11-18 and published on 2025-12-01, indicating recent disclosure. Mitigation requires prompt patching once available, enhanced input validation, and restricting file system access permissions to minimize exposure.

For European organizations, the primary impact of CVE-2025-65838 is the potential unauthorized disclosure of sensitive information hosted on PublicCMS platforms. This could include customer data, internal documents, or configuration files containing credentials or secrets. Such data breaches can lead to regulatory penalties under GDPR, reputational damage, and increased risk of follow-on attacks such as privilege escalation or lateral movement within networks. Organizations in sectors like government, finance, healthcare, and critical infrastructure that rely on PublicCMS for web content management are particularly vulnerable. The vulnerability's ease of exploitation without authentication and user interaction increases the likelihood of automated scanning and exploitation attempts. While availability and integrity are not directly affected, the confidentiality breach alone can have severe operational and compliance consequences. The absence of known exploits in the wild currently provides a window for proactive defense, but the risk of future exploitation remains high.

European organizations should immediately inventory their PublicCMS deployments to identify affected versions, specifically V5.202506.b. Until an official patch is released, implement strict input validation and sanitization on all file upload and path-related functionalities to prevent traversal sequences (e.g., ../). Employ web application firewalls (WAFs) with custom rules to detect and block path traversal attempts targeting the doUploadSitefile method. Restrict file system permissions for the web server process to the minimum necessary, preventing access to sensitive directories and files. Monitor logs for suspicious requests containing traversal patterns or unusual file access attempts. Segregate PublicCMS instances from critical internal networks to limit potential lateral movement. Once patches become available, prioritize their deployment in all environments. Additionally, conduct security awareness training for developers and administrators on secure coding practices related to file handling. Consider implementing runtime application self-protection (RASP) solutions to detect and block exploitation attempts in real time.