CVE-2026-34840
moderate-risk
Published 2026-04-02
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.
Do I need to act?
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0.03% chance of exploitation
EPSS score — low exploit probability
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Not on CISA KEV list
No confirmed active exploitation reported to CISA
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Patch status unknown
Check vendor advisories for fix availability and mitigation guidance
8
CVSS 8.1/10
High
NETWORK
/ LOW complexity
Affected Products (1)
Affected Vendors
33
/ 100
moderate-risk
Severity
28/34 · Critical
Exploitability
0/34 · Minimal
Exposure
5/34 · Minimal