Vulnerability Description
PACSgear MediaWriter 5.2.1 exposes a .NET Remoting TCP service on port 9000 via PacsgearMediaServerEngine.dll, registered with ObjectURIs RemoteObj and UIRemoteObj, without any authentication requirement. By exploiting the MarshalByRefObject object unmarshalling technique and implementing .NET WebClient class methods, an unauthenticated remote attacker can read and write arbitrary files on the host filesystem. The ObjectURIs are identical across all installations by default. Chaining the arbitrary file write primitive with DLL hijacking opportunities in the MediaWriter service (which runs as NT Authority\\SYSTEM and loads missing DLLs such as CRYPTBASE.DLL from the application directory) enables unauthenticated remote code execution as SYSTEM upon service restart.
CVSS Score
CRITICAL
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Hyland | Pacsgear | <= 5.2.1 |
Related Weaknesses (CWE)
References
- https://gist.github.com/VAMorales/dc679ecab30b7045fa07bf3249a034d8ExploitThird Party Advisory
- https://www.hyland.com/en/solutions/products/pacsgearProduct
- https://www.vulncheck.com/advisories/pacsgear-mediawriter-unauthenticated-rce-viThird Party AdvisoryVDB Entry
FAQ
What is CVE-2026-58127?
CVE-2026-58127 is a vulnerability with a CVSS score of 9.8 (CRITICAL). PACSgear MediaWriter 5.2.1 exposes a .NET Remoting TCP service on port 9000 via PacsgearMediaServerEngine.dll, registered with ObjectURIs RemoteObj and UIRemoteObj, without any authentication requirem...
How severe is CVE-2026-58127?
CVE-2026-58127 has been rated CRITICAL with a CVSS base score of 9.8/10. This is considered a critical vulnerability requiring immediate attention.
Is there a patch for CVE-2026-58127?
Check the references section above for vendor advisories and patch information. Affected products include: Hyland Pacsgear.