CVE-2026-34840 Details
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.
A vulnerability in OneUptime's SAML Single Sign-On (SSO) implementation prior to version 10.0.42 allows for authentication bypass through multi-assertion identity injection. The issue arises because signature verification and identity extraction processes are decoupled. An attacker can exploit this by prepending an unsigned assertion with a chosen identity to a signed assertion, bypassing authentication. This vulnerability affects OneUptime instances using SAML SSO with an Identity Provider (IdP) that produces assertion-level signatures.
Users can update to OneUptime version 10.0.42 or later, where this vulnerability has been patched.
Metrics
CVSS 4.0 Severity and Vector Strings:
No CVSS 4.0 data is available for this CVE.
CVSS 3.x Severity and Vector Strings:
No data available for CVSS Version 2.0 on this CVE.
CISA-ADP
Assessed Apr 2, 2026References to Advisories, Solutions, and Tools
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| URL | Source(s) | Tag(s) |
|---|---|---|
| https://github.com/OneUptime/oneuptime/commit/2fd7ede52f60444710628d6c1b34dee2ef9e57d1 | [email protected] | Patch |
| https://github.com/OneUptime/oneuptime/releases/tag/10.0.42 | [email protected] | ProductRelease Notes |
| https://github.com/OneUptime/oneuptime/security/advisories/GHSA-5w5c-766x-265g | [email protected] | ExploitMitigationVendor Advisory |
Weakness Enumeration
| CWE-ID | CWE Name | Source |
|---|---|---|
| CWE-347 | Improper Verification of Cryptographic Signature | [email protected] |
Affected Products
| Product | Versions |
|---|---|
| hackerbay oneuptime | < 10.0.42 |
CPE
Remediation
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Change History
5 change records found show changes
| Date | Action | Recorded By |
|---|---|---|
| Jul 24, 2026 | CVE Translated | [email protected] |
| Jun 17, 2026 | CVE Modified | [email protected] |
| Jun 17, 2026 | CVE Modified | CISA-ADP |
| Apr 13, 2026 | Initial Analysis | [email protected] |
| Apr 2, 2026 | New CVE Received | [email protected] |