Plaintext Password Disclosure via VBScript Sensor Error Message in Paessler PRTG Network Monitor (CVE-2026-4638) | HOL Guard CVE

High · CVSS 7.1CVE-2026-4638

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

Answer in brief

CVE-2026-4638 records a High severity (CVSS 7.1) vulnerability in Plaintext Password Disclosure via VBScript Sensor Error Message in Paessler PRTG Network Monitor. The current sources do not mark it as known exploited. The current feed maps Paessler GmbH/PRTG Network Monitor (generic). Check affected ranges and fixed versions before updating.

Analysis pending evidence review

HOL Guard separates source facts from reviewed analysis. See the methodology.

Published Sep 24, 2026Updated Sep 24, 2026Source checked Sep 24, 2026First seen by HOL Sep 24, 2026Material review Sep 24, 2026

Upstream Advisory

Key facts

Risk: High · CVSS 7.1
Exploitation: Not marked as known exploited
Affected software: 1 mapped package or product
Fix availability: Available

Why this deserves its current priority

CVSS is 7.1. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.

Analysis status

Analysis pending evidence review

Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.

Affected scope and exposure questions

The current feed maps Paessler GmbH/PRTG Network Monitor (generic). Check affected ranges and fixed versions before updating.

Mapped affected packages and fixed versions
Package	Affected range	Fixed version
Paessler GmbH/PRTG Network Monitorgeneric	>=0 <26.2.120.1449	26.2.120.1449

Recommended response

Check inventory. Check lockfiles and deployed manifests for Paessler GmbH/PRTG Network Monitor.
Review the reported fix. Update Paessler GmbH/PRTG Network Monitor to 26.2.120.1449 if you use the affected versions. Test the change in a non-production environment first.

Evidence timeline and material changes

Published upstream
Sep 24, 2026
Evidence: source:cvelist:source_dates:source-dates:record
Source modified
Sep 24, 2026
Evidence: source:cvelist:source_dates:source-dates:record
First seen by HOL
Sep 24, 2026

Sources and claim methodology

Upstream source description

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.

Quoted source text, attributed separately from HOL analysis.