CVE-2026-72691 PUBLISHED

OpenSignLabs opensignserver - Authentication Bypass

Assigner: TuranSec
Reserved: 10.08.2026 Published: 10.08.2026 Updated: 10.08.2026

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.

Metrics

CVSS Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
CVSS Score: 7.5

Product Status

Vendor OpenSignLabs
Product opensignserver
Versions Default: affected
  • affected from 0 to 2.37.0 (incl.)

Credits

  • Bobur Abdugafforov (Mahadsec) finder

References

Problem Types

  • CWE-288: Authentication Bypass Using an Alternate Path or Channel CWE