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TI-2026-04040 Aliases CVE-2026-4638GHSA-gh9q-9rjg-9rq2

Plaintext Password Disclosure via VBScript Sensor Error Message in Paessler PRTG Network Monitor

Priority LOW 31CWE-209Published · Updated

Key facts

Attack vector
Network
Privileges required
Low
User interaction
None
Attack complexity
Low
Attack requirements
None
Impact type
Information disclosure
Confidentiality · integrity · availability
High · None · None
Fix status
Fixed

Attack profile from CVSS 4.0 · CNA. Fix status from CNA. Impact type from CWE-209.

Summary

PRTG Network Monitor before version 26.2.120.1449 ships a demo EXE/Script sensor that multiplies two integer parameters using cscript.exe. If a non-numeric value is passed instead, cscript.exe raises a 'Type mismatch' runtime error that includes the offending parameter value in plaintext. PRTG provides a documented placeholder variable, %windowspassword, which resolves to the configured Windows/domain password used by PRTG and can be passed as a sensor parameter.  Any PRTG user who is not restricted to read-only access and is permitted to create sensors (the default for non-read-only users) can pass %windowspassword as an argument to the demo VBScript sensor, triggering the type-mismatch error and causing PRTG to display the plaintext password in the sensor's error output.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00305 23rd percentileScored 2026-11-07
Fix Fixed PRTG Network Monitor (Paessler GmbH): 26.2.120.1449

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
No
Technical impact
Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
PaesslerPRTG Network Monitorbefore 26.2.120.144926.2.120.1449Patch availableCNA
  • PRTG Network Monitor VendorPaessler Affected before 26.2.120.1449 Fixed in 26.2.120.1449 Patch available CNA

Remediation

  • Fix · CNA PRTG Network Monitor (Paessler GmbH) Fixed in 26.2.120.1449

Fixed in the same release

Records fixed by the same vendor advisory or release, as the CNA lists them.

  • Advisory ·

    Paessler PRTG Network Monitor — paessler.freshdesk.com/en/support/solutions/articles/760000…

    2 records Highest priority Priority MEDIUM 1 MEDIUM, 1 LOW

    Other records, highest priority first

    • TI-2026-04039 Reflected Cross-Site Scripting via URL Path in Paessler PRTG Network MonitorPriority MEDIUM 62
    Show all 2 records → Advisory →

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-4638
  2. 2026-10-03 Alias added: GHSA-gh9q-9rjg-9rq2

References

Patch 1

Advisory 2

Other 1

  • TI-2018-13743 PRTG Network Monitor before 18.2.40.1683 allows remote unauthenticated attackers to… KEVCVSS 3.1CRITICAL 9.8
  • TI-2018-06724 An issue was discovered in PRTG Network Monitor before 18.2.39. KEVCVSS 3.1HIGH 7.2
  • TI-2023-16035 A command injection was identified in PRTG 23.2.84.1566 and earlier versions in the Dicom… CVSS 3.1HIGH 7.2
  • TI-2022-16181 PRTG Network Monitor through 22.2.77.2204 does not prevent custom input for a device’s… CVSS 3.1MEDIUM 5.3
  • TI-2026-04039 Reflected Cross-Site Scripting via URL Path in Paessler PRTG Network Monitor CVSS 4.0MEDIUM 5.1
  • TI-2020-09265 PRTG Network Monitor before 20.1.57.1745 allows remote unauthenticated attackers to… CVSS 3.1MEDIUM 5.3
See all 46 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences