CVE-2026-72689Network attack vector

Unauthenticated contract disclosure via master-key document lookup

Published Aug 10, 2026 · Updated Aug 10, 2026

Broken object-level authorization in OpenSignServer through 2.37.0 allows remote attackers to read complete contract records. The getDocument Parse cloud function queries an attacker-supplied document identifier with useMasterKey, bypasses the object ACL, and returns the record with a pre-signed download URL. No authentication is required when IsEnableOTP is unset, the default configuration, exposing sender and signer PII and the associated document.

CVSS severity7.5
High
EPSS probability0.32%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Broken object-level authorization in OpenSignServer through 2.37.0 allows remote attackers to read complete contract records. The getDocument Parse cloud function queries an attacker-supplied document identifier with useMasterKey, bypasses the object ACL, and returns the record with a pre-signed download URL. No authentication is required when IsEnableOTP is unset, the default configuration, exposing sender and signer PII and the associated document.

The record

CVE
CVE-2026-72689
Published
Aug 10, 2026
Updated
Aug 10, 2026
Vendor
OpenSignLabs
Product
OpenSignServer
Classifications
CWE-639, T1190
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Aug 10, 2026CVE publishedPublication date reported by the CVE source.
  2. Aug 10, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=0 <=2.37.0

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

OpenSignLabs · OpenSignServerversion=0 <=2.37.0

Published CVSS scores

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

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-639Authorization Bypass Through User-Controlled Key
T1190Exploit Public-Facing Application

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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