CVE-2026-26221 json
Hyland OnBase Timer Service Unauthenticated .NET Remoting RCE
published 8mo ago modified 4mo ago also EUVD-2026-7376
- cvss
- 9.8
- version 3.1, CNA
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 1.3%
- EPSS 1.3% chance of exploitation in 30 days, percentile 70%
- public exploits
- 0
- none known
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.
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- Exploitation
- none
- Automatable
- yes
- Technical impact
- total
- Assessed
- 8mo ago
Exploit prediction
1.32% chance of exploitation in the next 30 days, higher than 70% of all scored CVEs (FIRST EPSS, 2026-11-09).
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 4.0 | 9.3 | CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N |
| CNA | 3.1 | 9.8 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H |
| CNA | 4.0 | 9.3 | CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X |
Affected products
- Hyland OnBase Workflow Timer Service
Classification
- Weakness
-
- CWE-502 Deserialization of Untrusted Data
References
-
community.hyland.com
/resources/bulletins-and-notices/223223-security-update-onbase-workflow-timer-service-bulletin-ob2025-03
vendor-advisory, mitigation, permissions-required
-
hyland.com
/en/solutions/products/onbase
product
-
vulncheck.com
/advisories/hyland-onbase-timer-services-unauthenticated-net-remoting-rce
third-party-advisory
Sources
- CVE List CVE-2026-26221
- NVD CVE-2026-26221
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