CVE-2026-72688: Opensignlabs Opensignserver

High severity, CVSS 7.5. EPSS: 0.6% chance of exploitation in the next 30 days.

A missing authentication vulnerability in OpenSignLabs opensignserver through 2.37.0 allows an unauthenticated remote attacker to read arbitrary stored documents via the fileupload Parse cloud function. The function mints MASTER_KEY-signed file access tokens for any caller-supplied URL without performing any session check, defeating the only access control protecting stored contract files.

Affected products

• Opensignlabs Opensignserver: up to and including 2.37.0

Published 2026-08-10. Last modified 2026-08-26.