CVE-2025-49028 is a Cross-Site Request Forgery (CSRF) vulnerability identified in Zoho ZeptoMail, a mail delivery service integrated within the Zoho Mail ecosystem. The vulnerability arises because the application fails to properly validate the origin of requests, allowing attackers to trick authenticated users into submitting malicious requests unknowingly. This can lead to stored Cross-Site Scripting (XSS) attacks, where malicious scripts are injected and persist within the application, potentially compromising user sessions, stealing sensitive information, or manipulating mail content. The vulnerability affects all versions of Zoho ZeptoMail up to 3.3.1. According to the CVSS 3.1 vector (AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:L), the attack can be launched remotely over the network with low attack complexity, requires no privileges, but does require user interaction (e.g., clicking a crafted link). The scope is changed, meaning the vulnerability affects components beyond the initially vulnerable module. The impact includes partial loss of confidentiality, integrity, and availability. Although no public exploits are known, the combination of CSRF and stored XSS increases the risk of persistent compromise. The vulnerability was reserved in May 2025 and published by the Patchstack assigner in December 2025. No patches or mitigation links are currently provided, indicating that affected organizations must monitor vendor updates closely.

For European organizations, this vulnerability poses a significant risk to the confidentiality and integrity of email communications and user data managed via Zoho ZeptoMail. Successful exploitation could allow attackers to execute unauthorized actions on behalf of users, inject persistent malicious scripts, and potentially spread malware or phishing campaigns internally. This could lead to data breaches, reputational damage, and disruption of critical communication channels. Given the widespread use of Zoho Mail in various sectors including SMEs, education, and government agencies across Europe, the impact could be broad. The vulnerability's ability to affect availability, though limited, could disrupt mail delivery or user access temporarily. Organizations relying on Zoho ZeptoMail for sensitive communications or regulatory compliance (e.g., GDPR) face increased risk of non-compliance and legal consequences if exploited. The lack of known exploits currently provides a window for proactive mitigation but also underscores the need for vigilance.

European organizations should immediately review their use of Zoho ZeptoMail and monitor vendor communications for official patches or updates addressing CVE-2025-49028. Until patches are available, implement strict Content Security Policy (CSP) headers to limit the impact of potential XSS payloads. Employ anti-CSRF tokens in all state-changing requests and validate the Origin and Referer headers server-side to detect and block unauthorized requests. Educate users about the risks of clicking unsolicited links or opening suspicious emails to reduce the likelihood of user interaction exploitation. Conduct regular security assessments and penetration tests focusing on web application security controls around Zoho ZeptoMail interfaces. Consider deploying Web Application Firewalls (WAFs) with custom rules to detect and block CSRF and XSS attack patterns. Finally, maintain robust incident response plans to quickly address any signs of compromise related to this vulnerability.