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TI-2026-27084 Aliases CVE-2026-34840

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

Priority HIGH 70CWE-347Published · Updated

Key facts

Attack vector
Network
Privileges required
Low
User interaction
None
Attack complexity
Low
Impact type
Security bypass
Confidentiality · integrity · availability
High · High · None
Fix status
Fixed

Attack profile from CVSS 3.1 · CNA. Fix status from CNA. Impact type from CWE-347.

Summary

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.

Why it matters now

Exploitation Proof of concept CISA SSVC · not in CISA KEV
EPSS 0.00269 19th percentileScored 2026-11-07
Public exploit Yes 1 exploit referenceTagged by NVD
Fix Fixed oneuptime (OneUptime): 10.0.42

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
Poc
Automatable
No
Technical impact
Total

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
OneUptimeoneuptimebefore 10.0.4210.0.42Patch availableCNA
  • oneuptime VendorOneUptime Affected before 10.0.42 Fixed in 10.0.42 Patch available CNA

CPE configurations NVD · 1

CPEVersionsRoleVendor
cpe:2.3:a:hackerbay:oneuptime:*:*:*:*:*:*:*:*before 10.0.42VulnerableOneUptime
  • cpe:2.3:a:hackerbay:oneuptime:*:*:*:*:*:*:*:* Versions before 10.0.42 Vulnerable ·OneUptime

Remediation

  • Fix · CNA oneuptime (OneUptime) Fixed in 10.0.42

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-34840

References

Exploit 1

Patch 1

Other 1

  • TI-2026-22090 OneUptime: OS Command Injection in Probe NetworkPathMonitor via unsanitized destination in traceroute exec() CVSS 3.1CRITICAL 10.0
  • TI-2026-27002 OneUptime: Missing Authentication on Notification Endpoints CVSS 3.1CRITICAL 9.1
  • TI-2026-25573 OneUptime: WhatsApp Webhook Missing Signature Verification CVSS 4.0HIGH 8.7
  • TI-2025-40534 OneUptime Unauthorized User Creation via API CVSS 4.0HIGH 8.8
  • TI-2026-25793 Protection mechanism failure in oneuptime CVSS 3.1CRITICAL 10.0
  • TI-2026-24835 OneUptime ClickHouse SQL Injection via Aggregate Query Parameters CVSS 3.1CRITICAL 10.0
See all 22 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences