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CVE-2026-34840

OneUptime SSO: Multi-Assertion Identity Injection via Decoupled Signature Verification

Published: Apr 2, 2026Updated: Apr 13, 2026 Sources: CVE List NVDCWE-347
NVD MITRE
8.1CVSSHIGH
EPSS Score
0.3%
Top 82.5%
CISA KEV
Not in KEV
Exploits
No Known Exploits
Remediation
Patch Available

Description

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 <Signature> 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.

CVSS Vector Breakdown

AV:NAC:LPR:LUI:NS:UC:HI:HA:N
Exploitability
AV:NAttack Vector
Network
AC:LAttack Complexity
Low
PR:LPrivileges Required
Low
UI:NUser Interaction
None
Scope
S:UScope
Unchanged
Impact
C:HConfidentiality
High
I:HIntegrity
High
A:NAvailability
None
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Weaknesses

CWE-347

Affected Products

oneuptimehackerbay
SaaS
Enterprise Software / itsm-monitoring
oneuptimeOneUptime
Mixed
Enterprise Software / itsm-monitoring
hackerbaycommercialEnterprise Softwareaka oneuptime
oneuptimecommercialEnterprise Softwareaka oneuptime.com

Attack Graph

Products CVE Techniques Tactics

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Exploitability

Official Patch Available
Workaround Available

MITRE ATT&CK

1 technique
Collection
View detailed technique mapping

References

https://github.com/OneUptime/oneuptime/commit/2fd7ede52f60444710628d6c1b34dee2ef9e57d1
github.com
https://github.com/OneUptime/oneuptime/releases/tag/10.0.42
github.com
https://github.com/OneUptime/oneuptime/security/advisories/GHSA-5w5c-766x-265g
github.com

Timeline

Published
Apr 2, 2026
Last Updated
Apr 13, 2026

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