CVE-2021-27340: OS4ED Opensis

Medium severity, CVSS 6.1. EPSS: 1.1% chance of exploitation in the next 30 days.

OpenSIS Community Edition version <= 7.6 is affected by a reflected XSS vulnerability in EmailCheck.php via the "opt" parameter.

Affected products

• OS4ED Opensis: up to and including 7.6

Published 2021-09-16. Last modified 2026-06-17.