CVE-2026-72691: Opensignlabs Opensignserver

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

An authentication bypass vulnerability in OpenSignLabs opensignserver through 2.37.0 allows an unauthenticated remote attacker to mint MASTER_KEY-signed file access tokens for arbitrary stored files via the getsignedurl Parse cloud function. The function skips its isAuthenticated check whenever any docId parameter is supplied, even one corresponding to no real document, allowing the authentication gate to be bypassed by supplying an arbitrary string as docId.

Affected products

• Opensignlabs Opensignserver: up to and including 2.37.0

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