oneuptime up to 10.0.41 SSO.ts isSignatureValid signature verification

CVSS Meta Temp Score
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CTI Interest Score
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7.0$0-$5k0.38

Summaryinfo

A vulnerability classified as critical was found in oneuptime up to 10.0.41. This impacts the function isSignatureValid of the file App/FeatureSet/Identity/Utils/SSO.ts. Executing a manipulation can lead to signature verification. This vulnerability is tracked as CVE-2026-34840. The attack can be launched remotely. No exploit exists. Upgrading the affected component is advised.

Detailsinfo

A vulnerability was found in oneuptime up to 10.0.41. It has been declared as critical. This vulnerability affects the function isSignatureValid of the file App/FeatureSet/Identity/Utils/SSO.ts. The manipulation with an unknown input leads to a signature verification vulnerability. The CWE definition for the vulnerability is CWE-347. The product does not verify, or incorrectly verifies, the cryptographic signature for data. As an impact it is known to affect confidentiality, integrity, and availability. CVE summarizes:

OneUptime is an open-source monitoring and observability platform. Prior to version 10.0.42, OneUptime's SAML SSO implementation (App/FeatureSet/Identity/Utils/SSO.ts) has decoupled signature verification and identity extraction. isSignatureValid() verifies the first element in the XML DOM using xml-crypto, while getEmail() always reads from assertion[0] via xml2js. An attacker can prepend an unsigned assertion containing an arbitrary identity before a legitimately signed assertion, resulting in authentication bypass. This issue has been patched in version 10.0.42.

The advisory is shared for download at github.com. This vulnerability was named CVE-2026-34840 since 03/30/2026. The exploitation appears to be easy. The attack can be initiated remotely. There are known technical details, but no exploit is available.

Upgrading to version 10.0.42 eliminates this vulnerability. The upgrade is hosted for download at github.com. Applying the patch 2fd7ede52f60444710628d6c1b34dee2ef9e57d1 is able to eliminate this problem. The bugfix is ready for download at github.com. The best possible mitigation is suggested to be upgrading to the latest version.

Once again VulDB remains the best source for vulnerability data.

Productinfo

Name

Version

License

Website

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 7.2
VulDB Meta Temp Score: 7.0

VulDB Base Score: 6.3
VulDB Temp Score: 6.0
VulDB Vector: 🔒
VulDB Reliability: 🔍

CNA Base Score: 8.1
CNA Vector (GitHub_M): 🔒

CVSSv2info

AVACAuCIA
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VectorComplexityAuthenticationConfidentialityIntegrityAvailability
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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Signature verification
CWE: CWE-347 / CWE-345
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Yes

Availability: 🔒
Status: Not defined
Price Prediction: 🔍
Current Price Estimation: 🔒

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Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: oneuptime 10.0.42
Patch: 2fd7ede52f60444710628d6c1b34dee2ef9e57d1

Timelineinfo

03/30/2026 CVE reserved
04/02/2026 +3 days Advisory disclosed
04/02/2026 +0 days VulDB entry created
04/03/2026 +0 days VulDB entry last update

Sourcesinfo

Product: github.com

Advisory: GHSA-5w5c-766x-265g
Status: Confirmed

CVE: CVE-2026-34840 (🔒)
GCVE (CVE): GCVE-0-2026-34840
GCVE (VulDB): GCVE-100-355012

Entryinfo

Created: 04/03/2026 00:00
Changes: 04/03/2026 00:00 (67)
Complete: 🔍
Cache ID: 216:B60:103

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