Vulnerability · Published Aug 10, 2026 · Assigned by TuranSec

CVE-2026-72688OpenSignLabs opensignserver - Missing Authentication for Critical Function

High 7.5

In plain English

A high-severity missing authentication 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 49% of all known vulnerabilities).

Severity (CVSS 3.1)7.5High

Exploit odds (30 days)0.6%top 50.6% of all CVEs

Exploited in the wildNo reportsCISA SSVC: none

Attack toolingNoneno public tooling known

Official description

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 (as reported)

Vendor	Product	Versions
OpenSignLabs	opensignserver	0 – through 2.37.0

Weakness: CWE-306 · 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