OpenSignLabs opensignserver - Authentication Bypass

MITRE NVD CVE.ORG JSON API

Summary

CVECVE-2026-72691
StatePUBLISHED
AssignerTuranSec
Source PriorityCVE Program / NVD first with legacy fallback
Published2026-08-10 13:20:39 UTC
Updated2026-08-10 19:17:33 UTC
DescriptionAn 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.

Risk And Classification

Primary CVSS: v3.1 7.5 HIGH from 309f9ea4-e3e9-4c6c-b79d-e8eb01244f2c

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

EPSS: 0.003930000 probability, percentile 0.321890000 (date 2026-08-11)

Problem Types: CWE-288 | CWE-288 CWE-288: Authentication Bypass Using an Alternate Path or Channel

VersionSourceTypeScoreSeverityVector
3.1309f9ea4-e3e9-4c6c-b79d-e8eb01244f2cSecondary7.5HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
3.1CNACVSS7.5HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

CVSS v3.1 Breakdown

Attack Vector
Network
Attack Complexity
Low
Privileges Required
None
User Interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
None
Availability
None

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

Vendor Declared Affected Products

SourceVendorProductVersionPlatforms
CNA OpenSignLabs Opensignserver affected 2.37.0 semver Not specified

References

ReferenceSourceLinkTags
github.com/OpenSignLabs/OpenSign 309f9ea4-e3e9-4c6c-b79d-e8eb01244f2c github.com
CVE Program record CVE.ORG www.cve.org canonical
NVD vulnerability detail NVD nvd.nist.gov canonical, analysis

Vendor Comments And Credit

Discovery Credit

CNA: Bobur Abdugafforov (Mahadsec) (en)

© CVE.report 2026

Use of this information constitutes acceptance for use in an AS IS condition. There are NO warranties, implied or otherwise, with regard to this information or its use. Any use of this information is at the user's risk. It is the responsibility of user to evaluate the accuracy, completeness or usefulness of any information, opinion, advice or other content. EACH USER WILL BE SOLELY RESPONSIBLE FOR ANY consequences of his or her direct or indirect use of this web site. ALL WARRANTIES OF ANY KIND ARE EXPRESSLY DISCLAIMED. This site will NOT BE LIABLE FOR ANY DIRECT, INDIRECT or any other kind of loss.

CVE, CWE, and OVAL are registred trademarks of The MITRE Corporation and the authoritative source of CVE content is MITRE's CVE web site. This site includes MITRE data granted under the following license.

Free CVE JSON API cve.report/api

CVE.report and Source URL Uptime Status status.cve.report