How serious is CVE-2026-26221?

This vulnerability has a CVSS score of 10 out of 10, classified as CRITICAL severity. Proof-of-concept exploit code is publicly available, making this an active threat.

Is there exploit code available for CVE-2026-26221?

Yes, proof-of-concept exploit code for CVE-2026-26221 is publicly available on GitHub and security research platforms. This increases the risk of active exploitation.

Which products are affected by CVE-2026-26221?

Check the official CVE details for a complete list of affected products and versions.

How do I fix CVE-2026-26221?

To remediate CVE-2026-26221, check for security patches from the vendor. Apply all available updates and security patches. If no patch is available, implement recommended workarounds or security controls to mitigate the risk.

CVE-2026-26221

Critical

|10.0

Exploit Available

Plain English Summary

AI-powered analysis for quick understanding

An attacker can exploit a critical vulnerability in Hyland OnBase to send malicious requests that allow them to read or write files on the server, potentially leading to remote code execution. This requires the attacker to have network access to the OnBase Workflow Timer Service, which listens on a specific port.

Technical Description

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.

CVSS Vector Analysis

Attack VectorNetwork

Attack ComplexityLow

Privileges RequiredNone

User InteractionNone

Confidentiality ImpactHigh

Integrity ImpactHigh

Availability ImpactHigh

ScopeChanged

Vector String

CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H/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

Exploit Resources

Search for proof-of-concept code and exploit modules

GitHub Search Exploit-DB Nuclei Templates Metasploit Vulners

Official References

NIST NVD

Est. Bounty

$15,000($5K-$15K)

Vendor Response

Grade APatched in 0 days

Quick Information

Published

Feb 13, 2026

7 days ago

Last Modified

Feb 13, 2026

7 days ago