CVE-2026-34840

HIGH

8.1

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.

CVE Details

CVSS v3.1 Score8.1

SeverityHIGH

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

Attack VectorNETWORK

ComplexityLOW

Privileges RequiredLOW

User InteractionNONE

Published4/2/2026

Last Modified4/3/2026

Sourcenvd

Honeypot Sightings0

Weaknesses (CWE)

CWE-347

References

https://github.com/OneUptime/oneuptime/commit/2fd7ede52f60444710628d6c1b34dee2ef9e57d1(security-advisories@github.com)

https://github.com/OneUptime/oneuptime/releases/tag/10.0.42(security-advisories@github.com)

https://github.com/OneUptime/oneuptime/security/advisories/GHSA-5w5c-766x-265g(security-advisories@github.com)

IOC Correlations

No correlations recorded

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