This vulnerability (CVE-2024-38678) is a stored XSS issue classified under CWE-79 affecting Calendar.online / Kalender.digital up to version 1.0.8. It arises from improper input sanitization during web page generation, enabling attackers to inject and persist malicious scripts that execute in the context of other users. The CVSS 3.1 base score is 6.5, reflecting network attack vector, low attack complexity, requiring low privileges and user interaction, with impacts on confidentiality, integrity, and availability at a low level. No vendor advisory or patch information is currently available, and the product is not a cloud service.

Successful exploitation could allow an attacker to execute arbitrary scripts in the context of the victim's browser, potentially leading to information disclosure, session hijacking, or other client-side impacts. The vulnerability affects confidentiality, integrity, and availability to a limited extent as indicated by the CVSS vector. There are no reports of active exploitation in the wild.

Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Until an official fix is released, users and administrators should exercise caution with untrusted input and consider implementing web application firewall (WAF) rules to detect and block XSS payloads. Avoid clicking on suspicious links or interacting with untrusted content within the affected application.