CVE-2025-7799 is a reflected Cross-Site Scripting (XSS) vulnerability classified under CWE-79, found in the e-Taxpayer Accounting Website developed by Zirve Information Technologies Inc. This vulnerability results from improper neutralization of input during web page generation, allowing attackers to inject malicious scripts that are reflected back to users. The flaw affects the website up to version 07082025 and does not require any authentication or user interaction to exploit, making it accessible remotely over the network. The CVSS 3.1 base score of 8.6 indicates a high-severity issue with low attack complexity and no privileges required. The impact primarily affects integrity, as attackers can execute arbitrary scripts in the context of the victim's browser, potentially leading to session hijacking, unauthorized actions, or phishing attacks. Confidentiality impact is limited but present due to possible data leakage, and availability impact is low. No patches or known exploits are currently reported, but the vulnerability's presence in a critical tax accounting platform raises concerns about potential misuse. The vulnerability was reserved in July 2025 and published in February 2026 by TR-CERT, highlighting its recognized security importance.

For European organizations, especially those relying on the Zirve e-Taxpayer Accounting Website, this vulnerability poses a significant risk to data integrity and user trust. Attackers exploiting this XSS flaw could perform unauthorized actions on behalf of legitimate users, manipulate accounting data, or steal sensitive tax information. This could lead to financial fraud, regulatory non-compliance, and reputational damage. The reflected nature of the XSS means phishing campaigns could be enhanced by embedding malicious links that execute scripts in the victim's browser. Although the confidentiality impact is moderate, the integrity compromise can disrupt critical tax processing workflows. The availability impact is low, but the overall operational risk is elevated due to potential cascading effects on tax reporting and compliance. European tax authorities or organizations using this platform must consider the threat serious, given the criticality of tax data and the potential for widespread exploitation if left unmitigated.

Organizations should immediately implement strict input validation and sanitization on all user-supplied data to prevent malicious script injection. Employ context-sensitive output encoding (e.g., HTML entity encoding) before rendering user input in web pages. Deploy a robust Content Security Policy (CSP) to restrict the execution of unauthorized scripts and reduce the impact of potential XSS attacks. Conduct thorough code reviews and security testing focusing on input handling in the e-Taxpayer Accounting Website. If possible, isolate the affected application environment and monitor for suspicious activities or anomalous requests indicative of exploitation attempts. Educate users about the risks of clicking untrusted links, especially those related to tax services. Engage with Zirve Information Technologies Inc. for official patches or updates and apply them promptly once available. Additionally, consider implementing Web Application Firewalls (WAF) with custom rules to detect and block reflected XSS payloads targeting this platform.