OpenSignLabs opensignserver - Missing Authentication for Critical Function

MITRE NVD CVE.ORG JSON API

Summary

CVECVE-2026-72688
StatePUBLISHED
AssignerTuranSec
Source PriorityCVE Program / NVD first with legacy fallback
Published2026-08-10 13:20:38 UTC
Updated2026-08-10 19:17:33 UTC
DescriptionA 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.

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: 0.005010000 probability, percentile 0.402700000 (date 2026-08-11)

Problem Types: CWE-306 | CWE-306 CWE-306: Missing Authentication for Critical Function

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)

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