CVE-2026-26221 — AI Deep Analysis Summary

Q: What is this vulnerability? (Essence + Consequences)

🚨 **Essence**: Unauthenticated .NET Remoting exposure in OnBase Workflow Timer Service. 💥 **Consequences**: Unsafe object deserialization → Arbitrary File Read/Write → **Remote Code Execution (RCE)**.

Q: Root Cause? (CWE/Flaw)

🛡️ **Root Cause**: **CWE-502** (Deserialization of Untrusted Data). The service exposes .NET Remoting without authentication, allowing attackers to inject malicious payloads.

Q: Who is affected? (Versions/Components)

🏢 **Affected**: **Hyland OnBase**. Specifically the **OnBase Workflow Timer Service**. Vendor: Hyland Software.

Q: What can hackers do? (Privileges/Data)

💀 **Attacker Capabilities**: Full system compromise. Can read/write arbitrary files and execute **arbitrary code** remotely. High impact on Confidentiality, Integrity, and Availability.

Q: Is exploitation threshold high? (Auth/Config)

⚡ **Exploitation Threshold**: **LOW**. **No Authentication** required. **Low Complexity**. Network accessible (AV:N). Easy to exploit.

Q: Is there a public Exp? (PoC/Wild Exploitation)

🔓 **Public Exploit**: **YES**. PoC available on GitHub: `CVE-2026-26221-Hyland-OnBase-Timer-Service-Unauthenticated-RCE`. Wild exploitation risk is high.

Q: How to self-check? (Features/Scanning)

🔍 **Self-Check**: Scan for exposed **.NET Remoting** ports/services on the Workflow Timer Service. Look for unauthenticated endpoints accepting serialized objects.

Q: Is it fixed officially? (Patch/Mitigation)

🩹 **Official Fix**: **YES**. Hyland released a security update (Bulletin OB2025-03). Check vendor advisory for patching instructions.

Q: What if no patch? (Workaround)

🚧 **No Patch?**: **Mitigation**: Block network access to the Workflow Timer Service. Disable .NET Remoting if possible. Restrict permissions. **Isolate** the component.

Q: Is it urgent? (Priority Suggestion)

🔥 **Urgency**: **CRITICAL**. CVSS **9.8** (High). Unauthenticated RCE with public PoC. **Patch Immediately** or isolate the service.

Updated May 06, 2026 CVSS 9.8 · Critical

This is a summary of the AI-generated 10-question deep analysis. The full version (longer answers, follow-up Q&A, related CVEs) requires login. Read the full analysis →

Q1What is this vulnerability? (Essence + Consequences)

🚨 **Essence**: Unauthenticated .NET Remoting exposure in OnBase Workflow Timer Service. 💥 **Consequences**: Unsafe object deserialization → Arbitrary File Read/Write → **Remote Code Execution (RCE)**.

Q2Root Cause? (CWE/Flaw)

🛡️ **Root Cause**: **CWE-502** (Deserialization of Untrusted Data). The service exposes .NET Remoting without authentication, allowing attackers to inject malicious payloads.

Q3Who is affected? (Versions/Components)

🏢 **Affected**: **Hyland OnBase**. Specifically the **OnBase Workflow Timer Service**. Vendor: Hyland Software.

Q4What can hackers do? (Privileges/Data)

💀 **Attacker Capabilities**: Full system compromise. Can read/write arbitrary files and execute **arbitrary code** remotely. High impact on Confidentiality, Integrity, and Availability.

Q5Is exploitation threshold high? (Auth/Config)

⚡ **Exploitation Threshold**: **LOW**. **No Authentication** required. **Low Complexity**. Network accessible (AV:N). Easy to exploit.

Q6Is there a public Exp? (PoC/Wild Exploitation)

🔓 **Public Exploit**: **YES**. PoC available on GitHub: `CVE-2026-26221-Hyland-OnBase-Timer-Service-Unauthenticated-RCE`. Wild exploitation risk is high.

Q7How to self-check? (Features/Scanning)

🔍 **Self-Check**: Scan for exposed **.NET Remoting** ports/services on the Workflow Timer Service. Look for unauthenticated endpoints accepting serialized objects.

Q8Is it fixed officially? (Patch/Mitigation)

🩹 **Official Fix**: **YES**. Hyland released a security update (Bulletin OB2025-03). Check vendor advisory for patching instructions.

Q9What if no patch? (Workaround)

🚧 **No Patch?**: **Mitigation**: Block network access to the Workflow Timer Service. Disable .NET Remoting if possible. Restrict permissions. **Isolate** the component.

Q10Is it urgent? (Priority Suggestion)

🔥 **Urgency**: **CRITICAL**. CVSS **9.8** (High). Unauthenticated RCE with public PoC. **Patch Immediately** or isolate the service.

Continue exploring

Vulnerability detail Full AI analysis (login) Hyland CWE-502