CVE-2025-63889 is a vulnerability identified in the ThinkPHP framework version 5.0.24, specifically within the fetch function located in the thinkphp\library\think\Template.php file. The flaw allows an attacker to read arbitrary files on the server by supplying a specially crafted file path in a template value. This occurs because the fetch function does not properly sanitize or validate the file path input, enabling directory traversal or direct file inclusion attacks. By exploiting this vulnerability, an attacker can access sensitive files such as configuration files, source code, or other data stored on the server that should not be publicly accessible. The vulnerability does not require authentication or user interaction, increasing its risk profile. Although no known exploits are currently reported in the wild, the nature of the vulnerability makes it a prime candidate for exploitation once publicized. The lack of a CVSS score means that severity must be inferred from the technical details: the vulnerability impacts confidentiality primarily, with potential indirect impacts on integrity if sensitive information is leveraged for further attacks. The scope is limited to systems running the vulnerable ThinkPHP version, but given the popularity of ThinkPHP in web applications, the affected surface is significant. The vulnerability was reserved in late October 2025 and published in November 2025, indicating recent discovery and disclosure.

For European organizations, this vulnerability poses a significant risk of unauthorized data disclosure. Sensitive internal files, including database credentials, API keys, or proprietary code, could be exposed, leading to potential data breaches or facilitating further attacks such as privilege escalation or remote code execution. Organizations relying on ThinkPHP 5.0.24 for web applications, particularly those handling personal data under GDPR, face compliance risks and reputational damage if exploited. The ease of exploitation without authentication increases the threat level, especially for public-facing web servers. Additionally, attackers could use the information gained to craft more sophisticated attacks, potentially compromising broader network segments. The impact is heightened in sectors with critical infrastructure or sensitive data, such as finance, healthcare, and government services within Europe.

Immediate mitigation should focus on upgrading ThinkPHP to a version where this vulnerability is patched once available. Until a patch is released, organizations should implement strict input validation and sanitization for all template-related inputs to prevent malicious file path injection. Employ web application firewalls (WAFs) with custom rules to detect and block suspicious file path patterns indicative of directory traversal or arbitrary file read attempts. Restrict file system permissions for the web server user to limit access to sensitive files and directories. Conduct thorough code reviews and audits of template usage to identify and remediate unsafe coding practices. Additionally, monitor logs for unusual access patterns or errors related to template rendering. For critical environments, consider isolating vulnerable applications or deploying temporary compensating controls such as disabling template features that accept external input until a fix is applied.