This vulnerability, identified as CVE-2026-40732, is an unauthenticated Cross-Site Scripting (XSS) issue in Notification for Telegram versions <= 3.5. It stems from improper neutralization of input during web page generation (CWE-79). The CVSS 3.1 base score is 7.1, indicating a high severity with network attack vector, low attack complexity, no privileges required, user interaction required, and impacts on confidentiality, integrity, and availability with scope changed. No patch or official remediation level has been published yet.

Successful exploitation of this vulnerability could allow an attacker to execute arbitrary scripts in the context of the affected application, potentially leading to partial disclosure of sensitive information, modification of data, and disruption of service availability. Since the vulnerability is unauthenticated, it can be exploited by remote attackers without credentials. The scope is changed, meaning the impact extends beyond the vulnerable component.

Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Until an official fix is available, consider applying temporary mitigations such as input validation and output encoding on user-supplied data if possible. Monitor vendor channels for updates and apply patches promptly once released.