CVE-2026-72691
OpenSignLabs opensignserver - Authentication Bypass
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.
INFO
Published Date :
Aug. 10, 2026, 1:20 p.m.
Last Modified :
Aug. 10, 2026, 1:20 p.m.
Remotely Exploit :
Yes !
Source :
309f9ea4-e3e9-4c6c-b79d-e8eb01244f2c
Affected Products
The following products are affected by CVE-2026-72691
vulnerability.
Even if cvefeed.io is aware of the exact versions of the
products
that
are
affected, the information is not represented in the table below.
No affected product recoded yet
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 3.1 | HIGH | 309f9ea4-e3e9-4c6c-b79d-e8eb01244f2c |
Solution
- Apply vendor updates for OpenSignLabs opensignserver.
- Restrict access to the getsignedurl Parse cloud function.
- Validate docId parameter rigorously.
- Ensure authentication checks are always performed.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-72691.
| URL | Resource |
|---|---|
| https://github.com/OpenSignLabs/OpenSign |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-72691 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-72691
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-72691 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-72691 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
New CVE Received by 309f9ea4-e3e9-4c6c-b79d-e8eb01244f2c
Aug. 10, 2026
Action Type Old Value New Value Added Affected [{'vendor': 'OpenSignLabs', 'product': 'opensignserver', 'versions': [{'status': 'affected', 'version': '0', 'versionType': 'semver', 'lessThanOrEqual': '2.37.0'}], 'defaultStatus': 'affected'}] Added 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. Added CVSS V3.1 AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N Added CWE CWE-288 Added Reference https://github.com/OpenSignLabs/OpenSign