CVE-2026-34840

HIGH

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

Title source: cna

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.

Scores

CVSS v3 8.1
EPSS 0.0006
EPSS Percentile 18.8%
Attack Vector NETWORK
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N

Details

CWE
CWE-347
Status published
Products (2)
hackerbay/oneuptime < 10.0.42
OneUptime/oneuptime < 10.0.42
Published Apr 02, 2026
Tracked Since Apr 03, 2026