Plaintext Password Disclosure via VBScript Sensor Error Message in Paessler PRTG Network Monitor
Summary
| CVE | CVE-2026-4638 |
|---|---|
| State | PUBLISHED |
| Assigner | SEC-VLab |
| Source Priority | CVE Program / NVD first with legacy fallback |
| Published | 2026-09-24 11:16:45 UTC |
| Updated | 2026-09-24 20:43:32 UTC |
| 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. |
Risk And Classification
Primary CVSS: v4.0 7.1 HIGH from 551230f0-3615-47bd-b7cc-93e92e730bbf
CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:N/VA:N/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
EPSS: 0.002680000 probability, percentile 0.169010000 (date 2026-09-25)
Problem Types: CWE-209 | CWE-209 CWE-209 Generation of error message containing sensitive information
| Version | Source | Type | Score | Severity | Vector |
|---|---|---|---|---|---|
| 4.0 | 551230f0-3615-47bd-b7cc-93e92e730bbf | Secondary | 7.1 | HIGH | CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N/E:X/C... |
| 4.0 | CNA | CVSS | 7.1 | HIGH | CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N |
CVSS v4.0 Breakdown
CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:N/VA:N/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
Vendor Declared Affected Products
| Source | Vendor | Product | Version | Platforms |
|---|---|---|---|---|
| CNA | Paessler GmbH | PRTG Network Monitor | affected 26.2.120.1449 custom | Not specified |
References
| Reference | Source | Link | Tags |
|---|---|---|---|
| www.paessler.com/prtg/prtg-network-monitor | 551230f0-3615-47bd-b7cc-93e92e730bbf | www.paessler.com | |
| paessler.freshdesk.com/en/support/solutions/articles/76000088640 | 551230f0-3615-47bd-b7cc-93e92e730bbf | paessler.freshdesk.com | |
| www.paessler.com/de/download | 551230f0-3615-47bd-b7cc-93e92e730bbf | www.paessler.com | |
| r.sec-consult.com/paessler | 551230f0-3615-47bd-b7cc-93e92e730bbf | r.sec-consult.com | |
| CVE Program record | CVE.ORG | www.cve.org | canonical |
| NVD vulnerability detail | NVD | nvd.nist.gov | canonical, analysis |
Vendor Comments And Credit
Discovery Credit
CNA: J. Kruchem, SEC Consult Vulnerability Lab (en)
CNA: S. Michlits, SEC Consult Vulnerability Lab (en)
Additional Advisory Data
Solutions
CNA: Upgrade to Paessler PRTG Network Monitor version 26.2.120.1449 or later.