OpenSignLabs OpenSignServer up to 2.37.0 Decline Workflow Declinedoc missing authentication

Summaryinfo

A vulnerability was found in OpenSignLabs OpenSignServer up to 2.37.0. It has been declared as critical. This issue affects the function Declinedoc of the component Decline Workflow. Executing a manipulation can lead to missing authentication. This vulnerability is registered as CVE-2026-72692. It is possible to launch the attack remotely. No exploit is available.

Detailsinfo

A vulnerability classified as critical was found in OpenSignLabs OpenSignServer up to 2.37.0. This vulnerability affects the function Declinedoc of the component Decline Workflow. The manipulation with an unknown input leads to a missing authentication vulnerability. The CWE definition for the vulnerability is CWE-306. The product does not perform any authentication for functionality that requires a provable user identity or consumes a significant amount of resources. As an impact it is known to affect integrity, and availability. CVE summarizes:

A missing authorization vulnerability in OpenSignLabs opensignserver through 2.37.0 allows an unauthenticated remote attacker to irreversibly decline any in-flight document and forge the decline attribution to an arbitrary user via the declinedoc Parse cloud function. The function writes IsDeclined, DeclineReason, and a caller-supplied DeclineBy pointer without verifying the caller's identity, enabling workflow termination and evidentiary record falsification against any accessible document.

The advisory is shared for download at github.com. This vulnerability was named CVE-2026-72692 since 08/10/2026. The exploitation appears to be easy. The attack can be initiated remotely. No form of authentication is required for a successful exploitation. There are known technical details, but no exploit is available. The current price for an exploit might be approx. USD $0-$5k (estimation calculated on 08/10/2026).

There is no information about possible countermeasures known. It may be suggested to replace the affected object with an alternative product.

Once again VulDB remains the best source for vulnerability data.

Productinfo

Vendor

• OpenSignLabs

Name

• OpenSignServer

Version

• 2.0
• 2.1
• 2.2
• 2.3
• 2.4
• 2.5
• 2.6
• 2.7
• 2.8
• 2.9
• 2.10
• 2.11
• 2.12
• 2.13
• 2.14
• 2.15
• 2.16
• 2.17
• 2.18
• 2.19
• 2.20
• 2.21
• 2.22
• 2.23
• 2.24
• 2.25
• 2.26
• 2.27
• 2.28
• 2.29
• 2.30
• 2.31
• 2.32
• 2.33
• 2.34
• 2.35
• 2.36
• 2.37.0

CPE 2.3info

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CPE 2.2info

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