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Public proof of concept

CVE-2026-58127

A public proof of concept exists; no exploitation attested.

  • Published2026-07-01
  • WeaknessCWE-306 · CWE-502

Am I affected?

With a domain, we read the version its public headers and pages expose. A distribution build can carry the fix under an older number.

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.

Timeline

dates in UTC
  1. 2026-07-0116:16CVE publishedNVD

Versions per branch

NVD
Hyland pacsgear
BranchAffectedFixed in
5.2≤ 5.2.1no fix published

as publishedRanges as NVD and OSV publish them; a distribution’s build can be fixed under an older number.

Products declared by the CNA1 product

As VulnCheck, the CNA that assigned this CVE, declared them in the CVE record; versions as written.

  • Hyland PACSgear MediaWriterother versions: affected
    Affected
    • = 5.2.1no fix statedsemver

Source: the CNA record (CVE Program), © The MITRE Corporation,CVE Terms of UseCVE recordupdated 2026-07-01

Fix

No fix published by the sources we read yet. NVD record

Detection

Nuclei template
none so far
ProjectDiscovery
Exploit-DB
no entry
Exploit-DB
Proof of concept
Metasploit modules
none listed
Metasploit Framework

Sources

  • NVDCVE recordread 2026-10-26
  • CISA-ADPSSVC decisionpoc2026-07-01
  • CNACVSS 4.09.3known since 2026-10-26
  • CNACVSS 3.19.8known since 2026-10-26
  • CNAweakness (CWE)CWE-306, CWE-502known since 2026-10-26
  • FIRST EPSSEPSS score1.9 %2026-11-08
  • GitHub Advisoriesadvisory—

Identifiers

Technical details

CVSS v3 Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
CVSS 4.0 vector
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
Published
2026-07-01
Last Modified
2026-10-25
NVD status
Analyzed
GitHub Advisory
GHSA-9h7v-mf98-p6r6

Frequently asked questions

What is CVE-2026-58127?

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.

Is CVE-2026-58127 actively exploited?

A proof-of-concept exploit exists for CVE-2026-58127, but active exploitation has not been confirmed at this time.

What is the CVSS score for CVE-2026-58127?

CVE-2026-58127 has a CVSS v3 base score of 9.8 (CRITICAL severity), with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

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