CVE-2025-10246 is a cross-site scripting (XSS) vulnerability identified in the PHP-Code-For-Unlimited-File-Upload project maintained by lokibhardwaj. The vulnerability exists in the /f.php file, specifically in the handling of the 'h' parameter. An attacker can manipulate this parameter to inject malicious scripts, which are then executed in the context of the victim's browser. This type of vulnerability allows remote attackers to execute arbitrary JavaScript code without authentication or privileges, potentially leading to session hijacking, defacement, or redirection to malicious sites. The product follows a rolling release model, so exact affected versions are not clearly delineated beyond the commit hash 124fe96324915490c81eaf7db3234b0b4e4bab3c. The vendor has not responded to disclosure attempts, and no official patches are currently available. The vulnerability has a CVSS 4.0 base score of 5.1, indicating a medium severity level. The vector indicates network attack vector, low attack complexity, no privileges required, but user interaction is necessary for exploitation. The vulnerability does not affect confidentiality or availability significantly but impacts integrity via script injection and user trust. No known exploits are currently observed in the wild, but public exploit code exists, increasing the risk of exploitation.

For European organizations, this XSS vulnerability poses a moderate risk primarily to web applications that integrate or rely on the PHP-Code-For-Unlimited-File-Upload component. Successful exploitation could lead to theft of user credentials, session tokens, or other sensitive information via malicious script execution. This can facilitate further attacks such as account takeover or phishing. Additionally, compromised web pages can damage organizational reputation and user trust, especially in sectors handling sensitive personal data under GDPR regulations. While the vulnerability does not directly compromise backend systems or data integrity, the potential for lateral attacks through stolen credentials or session hijacking is a concern. Organizations using this component in customer-facing portals, intranets, or administrative interfaces are particularly at risk. The lack of vendor response and patches increases exposure time, necessitating proactive mitigation.

European organizations should immediately audit their use of the PHP-Code-For-Unlimited-File-Upload component to identify affected instances. As no official patch is available, temporary mitigations include implementing strict input validation and output encoding on the 'h' parameter to neutralize malicious scripts. Employing Content Security Policy (CSP) headers can reduce the impact of injected scripts by restricting script execution sources. Web Application Firewalls (WAFs) should be configured to detect and block typical XSS payloads targeting this parameter. Additionally, organizations should monitor web logs for suspicious requests to /f.php and educate users about phishing risks. If feasible, replacing or removing the vulnerable component until a patch is released is recommended. Regular security testing and code reviews should be conducted to detect similar vulnerabilities proactively.