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CVE-2026-26221

Hyland OnBase Timer Service Unauthenticated .NET Remoting RCE

Published
Last modified
published
Not listed in CISA KEV
1 proof of concept on GitHub
  • Exploitation: none
  • Automatable: yes
  • Technical impact: total

Summary

Hyland OnBase contains an unauthenticated .NET Remoting exposure in the OnBase Workflow Timer Service (Hyland.Core.Workflow.NTService.exe). An attacker who can reach the service can send crafted .NET Remoting requests to default HTTP channel endpoints on TCP/8900 (e.g., TimerServiceAPI.rem and TimerServiceEvents.rem for Workflow) to trigger unsafe object unmarshalling, enabling arbitrary file read/write. By writing attacker-controlled content into web-accessible locations or chaining with other OnBase features, this can lead to remote code execution. The same primitive can be abused by supplying a UNC path to coerce outbound NTLM authentication (SMB coercion) to an attacker-controlled host.

Timeline

  1. CVE published
  2. CISA SSVC assessment

    Exploitation: none · Automatable: yes · Technical impact: total

  3. Record last updated

Affected versions

  • Hyland OnBase Workflow Timer Service

    From 8.0 · through 17.0.0

References 4

hyland.com

community.hyland.com

vulncheck.com

GitHub · mbanyamer/CVE-2026-26221-Hyland-OnBase-Timer-Service-Unauthenticated-RCE