Vulnerability · Published Aug 10, 2026 · Assigned by TuranSec

CVE-2026-72691OpenSignLabs opensignserver - Authentication Bypass

High 7.5

In plain English

A high-severity authentication bypass in opensignserver from OpenSignLabs. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.6% (higher than 51% of all known vulnerabilities).

Severity (CVSS 3.1)7.5High

Exploit odds (30 days)0.6%top 48.8% of all CVEs

Exploited in the wildNo reportsCISA SSVC: none

Attack toolingNoneno public tooling known

Official description

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 (as reported)

Vendor	Product	Versions
OpenSignLabs	opensignserver	0 – through 2.37.0

Weakness: CWE-288 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

References

OpenSign GitHub Repository third-party-advisory