CVE-2026-25529: Postalserver Postal

High severity, CVSS 8.1. EPSS: 0.4% chance of exploitation in the next 30 days.

Postal is an open source SMTP server. Postal versions less than 3.3.5 had a HTML injection vulnerability that allowed unescaped data to be included in the admin interface. The primary way for unescaped data to be added is via the API's "send/raw" method. This could allow arbitrary HTML to be injected in to the page which may modify the page in a misleading way or allow for unauthorised javascript to be executed. Fixed in 3.3.5 and higher.

Affected products

• Postalserver Postal: before 3.3.5 (fixed in 3.3.5)

Published 2026-03-12. Last modified 2026-06-17.