Search
Find a vulnerability
Search criteria
4 vulnerabilities found for PRTG Network Monitor by Paessler GmbH
CVE-2026-4638 (GCVE-0-2026-4638)
Vulnerability from nvd – Published: 2026-09-24 10:57 – Updated: 2026-09-24 12:14
VLAI
EPSS
VEX
Title
Plaintext Password Disclosure via VBScript Sensor Error Message in Paessler PRTG Network Monitor
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.
Severity
SSVC
Exploitation: none
Automatable: no
Technical Impact: partial
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2026-09-24 12:13 UTC
CWE
- CWE-209 - Generation of error message containing sensitive information
Assigner
References
4 references
| URL | Tags |
|---|---|
| https://r.sec-consult.com/paessler | third-party-advisory |
| https://paessler.freshdesk.com/en/support/solutio… | vendor-advisory |
| https://www.paessler.com/de/download/ | patch |
| https://www.paessler.com/prtg/prtg-network-monitor | product |
Impacted products
1 product
| Vendor | Product | Version | |
|---|---|---|---|
| Paessler GmbH | PRTG Network Monitor |
Affected:
0 , < 26.2.120.1449
(custom)
|
{
"containers": {
"adp": [
{
"metrics": [
{
"other": {
"content": {
"id": "CVE-2026-4638",
"options": [
{
"Exploitation": "none"
},
{
"Automatable": "no"
},
{
"Technical Impact": "partial"
}
],
"role": "CISA Coordinator",
"timestamp": "2026-09-24T12:13:17.297572Z",
"version": "2.0.3"
},
"type": "ssvc"
}
}
],
"providerMetadata": {
"dateUpdated": "2026-09-24T12:14:20.861Z",
"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"shortName": "CISA-ADP"
},
"title": "CISA ADP Vulnrichment"
}
],
"cna": {
"affected": [
{
"defaultStatus": "unaffected",
"product": "PRTG Network Monitor",
"vendor": "Paessler GmbH",
"versions": [
{
"lessThan": "26.2.120.1449",
"status": "affected",
"version": "0",
"versionType": "custom"
}
]
}
],
"credits": [
{
"lang": "en",
"type": "finder",
"value": "J. Kruchem, SEC Consult Vulnerability Lab"
},
{
"lang": "en",
"type": "finder",
"value": "S. Michlits, SEC Consult Vulnerability Lab"
}
],
"descriptions": [
{
"lang": "en",
"supportingMedia": [
{
"base64": false,
"type": "text/html",
"value": "\u003cdiv\u003e\u003cspan\u003ePRTG 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 \u0027Type mismatch\u0027 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.\u0026nbsp;\u003c/span\u003e\u003c/div\u003e\u003cdiv\u003e\u003cspan\u003e\u003cbr\u003e\u003c/span\u003e\u003c/div\u003e\u003cdiv\u003e\u003cspan\u003eAny 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\u0027s error output.\u003c/span\u003e\u003c/div\u003e"
}
],
"value": "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 \u0027Type mismatch\u0027 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.\u00a0\n\n\n\n\nAny 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\u0027s error output."
}
],
"impacts": [
{
"capecId": "CAPEC-54",
"descriptions": [
{
"lang": "en",
"value": "CAPEC-54 Query System for Information"
}
]
}
],
"metrics": [
{
"cvssV4_0": {
"Automatable": "NOT_DEFINED",
"Recovery": "NOT_DEFINED",
"Safety": "NOT_DEFINED",
"attackComplexity": "LOW",
"attackRequirements": "NONE",
"attackVector": "NETWORK",
"baseScore": 7.1,
"baseSeverity": "HIGH",
"exploitMaturity": "NOT_DEFINED",
"privilegesRequired": "LOW",
"providerUrgency": "NOT_DEFINED",
"subAvailabilityImpact": "NONE",
"subConfidentialityImpact": "NONE",
"subIntegrityImpact": "NONE",
"userInteraction": "NONE",
"valueDensity": "NOT_DEFINED",
"vectorString": "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",
"version": "4.0",
"vulnAvailabilityImpact": "NONE",
"vulnConfidentialityImpact": "HIGH",
"vulnIntegrityImpact": "NONE",
"vulnerabilityResponseEffort": "NOT_DEFINED"
},
"format": "CVSS",
"scenarios": [
{
"lang": "en",
"value": "GENERAL"
}
]
}
],
"problemTypes": [
{
"descriptions": [
{
"cweId": "CWE-209",
"description": "CWE-209 Generation of error message containing sensitive information",
"lang": "en",
"type": "CWE"
}
]
}
],
"providerMetadata": {
"dateUpdated": "2026-09-24T10:57:54.203Z",
"orgId": "551230f0-3615-47bd-b7cc-93e92e730bbf",
"shortName": "SEC-VLab"
},
"references": [
{
"tags": [
"third-party-advisory"
],
"url": "https://r.sec-consult.com/paessler"
},
{
"tags": [
"vendor-advisory"
],
"url": "https://paessler.freshdesk.com/en/support/solutions/articles/76000088640"
},
{
"tags": [
"patch"
],
"url": "https://www.paessler.com/de/download/"
},
{
"tags": [
"product"
],
"url": "https://www.paessler.com/prtg/prtg-network-monitor"
}
],
"solutions": [
{
"lang": "en",
"supportingMedia": [
{
"base64": false,
"type": "text/html",
"value": "Upgrade to Paessler PRTG Network Monitor version 26.2.120.1449 or later."
}
],
"value": "Upgrade to Paessler PRTG Network Monitor version 26.2.120.1449 or later."
}
],
"source": {
"discovery": "EXTERNAL"
},
"title": "Plaintext Password Disclosure via VBScript Sensor Error Message in Paessler PRTG Network Monitor",
"x_generator": {
"engine": "Vulnogram 1.0.5"
}
}
},
"cveMetadata": {
"assignerOrgId": "551230f0-3615-47bd-b7cc-93e92e730bbf",
"assignerShortName": "SEC-VLab",
"cveId": "CVE-2026-4638",
"datePublished": "2026-09-24T10:57:54.203Z",
"dateReserved": "2026-03-23T10:32:11.997Z",
"dateUpdated": "2026-09-24T12:14:20.861Z",
"state": "PUBLISHED"
},
"dataType": "CVE_RECORD",
"dataVersion": "5.2"
}
CVE-2026-4637 (GCVE-0-2026-4637)
Vulnerability from nvd – Published: 2026-09-24 10:05 – Updated: 2026-09-24 12:20
VLAI
EPSS
VEX
Title
Reflected Cross-Site Scripting via URL Path in Paessler PRTG Network Monitor
Summary
Paessler PRTG Network Monitor before version 26.2.120.1449 is affected by a reflected Cross-Site Scripting (XSS) vulnerability. When a request is made for a non-existent resource ending in \".htm\", the web interface returns an HTTP 403 \"Forbidden Path\" error page that echoes the requested URL path into the HTML response body without proper output encoding or sanitization.
An unauthenticated, remote attacker can craft a URL containing an HTML/JavaScript payload in the path (e.g. https:////welcome.htm) and, once a victim with an active PRTG session opens the crafted link, execute arbitrary JavaScript in the security context of the PRTG web interface. Because the PRTG session cookie is not protected with the HttpOnly attribute, successful exploitation allows the attacker to read and exfiltrate the victim's session cookie, potentially leading to session hijacking.
Severity
SSVC
Exploitation: poc
Automatable: yes
Technical Impact: partial
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2026-09-24 12:19 UTC
CWE
- CWE-79 - Improper neutralization of input during web page generation ('cross-site scripting')
Assigner
References
5 references
| URL | Tags |
|---|---|
| https://paessler.freshdesk.com/en/support/solutio… | vendor-advisory |
| https://www.paessler.com/de/download/ | patch |
| https://www.paessler.com/prtg/prtg-network-monitor | product |
| https://r.sec-consult.com/paessler | third-party-advisory |
| https://sec-consult.com/vulnerability-lab/advisor… | exploit |
Impacted products
1 product
| Vendor | Product | Version | |
|---|---|---|---|
| Paessler GmbH | PRTG Network Monitor |
Affected:
0 , < 26.2.120.1449
(custom)
|
{
"containers": {
"adp": [
{
"metrics": [
{
"other": {
"content": {
"id": "CVE-2026-4637",
"options": [
{
"Exploitation": "poc"
},
{
"Automatable": "yes"
},
{
"Technical Impact": "partial"
}
],
"role": "CISA Coordinator",
"timestamp": "2026-09-24T12:19:37.419469Z",
"version": "2.0.3"
},
"type": "ssvc"
}
}
],
"providerMetadata": {
"dateUpdated": "2026-09-24T12:20:41.854Z",
"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"shortName": "CISA-ADP"
},
"references": [
{
"tags": [
"exploit"
],
"url": "https://sec-consult.com/vulnerability-lab/advisory/multiple-vulnerabilities-in-paessler-prtg-network-monitor/"
}
],
"title": "CISA ADP Vulnrichment"
}
],
"cna": {
"affected": [
{
"defaultStatus": "unaffected",
"product": "PRTG Network Monitor",
"vendor": "Paessler GmbH",
"versions": [
{
"lessThan": "26.2.120.1449",
"status": "affected",
"version": "0",
"versionType": "custom"
}
]
}
],
"credits": [
{
"lang": "en",
"type": "finder",
"value": "J. Kruchem, SEC Consult Vulnerability Lab"
},
{
"lang": "en",
"type": "finder",
"value": "S. Michlits, SEC Consult Vulnerability Lab"
}
],
"descriptions": [
{
"lang": "en",
"supportingMedia": [
{
"base64": false,
"type": "text/html",
"value": "\u003cdiv\u003e\u003cspan\u003ePaessler PRTG Network Monitor before version 26.2.120.1449 is affected by a reflected Cross-Site Scripting (XSS) vulnerability. When a request is made for a non-existent resource ending in \\\".htm\\\", the web interface returns an HTTP 403 \\\"Forbidden Path\\\" error page that echoes the requested URL path into the HTML response body without proper output encoding or sanitization.\u003c/span\u003e\u003c/div\u003e\u003cdiv\u003e\u003cspan\u003e\u003cbr\u003e\u003c/span\u003e\u003c/div\u003e\u003cdiv\u003eAn unauthenticated, remote attacker can craft a URL containing an HTML/JavaScript payload in the path (e.g. https:////welcome.htm) and, once a victim with an active PRTG session opens the crafted link, execute arbitrary JavaScript in the security context of the PRTG web interface. Because the PRTG session cookie is not protected with the HttpOnly attribute, successful exploitation allows the attacker to read and exfiltrate the victim\u0027s session cookie, potentially leading to session hijacking.\u003c/div\u003e"
}
],
"value": "Paessler PRTG Network Monitor before version 26.2.120.1449 is affected by a reflected Cross-Site Scripting (XSS) vulnerability. When a request is made for a non-existent resource ending in \\\".htm\\\", the web interface returns an HTTP 403 \\\"Forbidden Path\\\" error page that echoes the requested URL path into the HTML response body without proper output encoding or sanitization.\n\n\n\n\nAn unauthenticated, remote attacker can craft a URL containing an HTML/JavaScript payload in the path (e.g. https:////welcome.htm) and, once a victim with an active PRTG session opens the crafted link, execute arbitrary JavaScript in the security context of the PRTG web interface. Because the PRTG session cookie is not protected with the HttpOnly attribute, successful exploitation allows the attacker to read and exfiltrate the victim\u0027s session cookie, potentially leading to session hijacking."
}
],
"impacts": [
{
"capecId": "CAPEC-591",
"descriptions": [
{
"lang": "en",
"value": "CAPEC-591 Reflected XSS"
}
]
}
],
"metrics": [
{
"cvssV4_0": {
"Automatable": "NOT_DEFINED",
"Recovery": "NOT_DEFINED",
"Safety": "NOT_DEFINED",
"attackComplexity": "LOW",
"attackRequirements": "NONE",
"attackVector": "NETWORK",
"baseScore": 5.1,
"baseSeverity": "MEDIUM",
"exploitMaturity": "NOT_DEFINED",
"privilegesRequired": "NONE",
"providerUrgency": "NOT_DEFINED",
"subAvailabilityImpact": "NONE",
"subConfidentialityImpact": "LOW",
"subIntegrityImpact": "LOW",
"userInteraction": "ACTIVE",
"valueDensity": "NOT_DEFINED",
"vectorString": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N",
"version": "4.0",
"vulnAvailabilityImpact": "NONE",
"vulnConfidentialityImpact": "NONE",
"vulnIntegrityImpact": "NONE",
"vulnerabilityResponseEffort": "NOT_DEFINED"
},
"format": "CVSS",
"scenarios": [
{
"lang": "en",
"value": "GENERAL"
}
]
}
],
"problemTypes": [
{
"descriptions": [
{
"cweId": "CWE-79",
"description": "CWE-79 Improper neutralization of input during web page generation (\u0027cross-site scripting\u0027)",
"lang": "en",
"type": "CWE"
}
]
}
],
"providerMetadata": {
"dateUpdated": "2026-09-24T10:05:06.998Z",
"orgId": "551230f0-3615-47bd-b7cc-93e92e730bbf",
"shortName": "SEC-VLab"
},
"references": [
{
"tags": [
"vendor-advisory"
],
"url": "https://paessler.freshdesk.com/en/support/solutions/articles/76000088640"
},
{
"tags": [
"patch"
],
"url": "https://www.paessler.com/de/download/"
},
{
"tags": [
"product"
],
"url": "https://www.paessler.com/prtg/prtg-network-monitor"
},
{
"tags": [
"third-party-advisory"
],
"url": "https://r.sec-consult.com/paessler"
}
],
"solutions": [
{
"lang": "en",
"supportingMedia": [
{
"base64": false,
"type": "text/html",
"value": "Upgrade to Paessler PRTG Network Monitor version 26.2.120.1449 or later."
}
],
"value": "Upgrade to Paessler PRTG Network Monitor version 26.2.120.1449 or later."
}
],
"source": {
"discovery": "EXTERNAL"
},
"title": "Reflected Cross-Site Scripting via URL Path in Paessler PRTG Network Monitor",
"x_generator": {
"engine": "Vulnogram 1.0.5"
}
}
},
"cveMetadata": {
"assignerOrgId": "551230f0-3615-47bd-b7cc-93e92e730bbf",
"assignerShortName": "SEC-VLab",
"cveId": "CVE-2026-4637",
"datePublished": "2026-09-24T10:05:06.998Z",
"dateReserved": "2026-03-23T10:31:35.511Z",
"dateUpdated": "2026-09-24T12:20:41.854Z",
"state": "PUBLISHED"
},
"dataType": "CVE_RECORD",
"dataVersion": "5.2"
}
CVE-2026-4638 (GCVE-0-2026-4638)
Vulnerability from cvelistv5 – Published: 2026-09-24 10:57 – Updated: 2026-09-24 12:14
VLAI
EPSS
VEX
Title
Plaintext Password Disclosure via VBScript Sensor Error Message in Paessler PRTG Network Monitor
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.
Severity
SSVC
Exploitation: none
Automatable: no
Technical Impact: partial
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2026-09-24 12:13 UTC
CWE
- CWE-209 - Generation of error message containing sensitive information
Assigner
References
4 references
| URL | Tags |
|---|---|
| https://r.sec-consult.com/paessler | third-party-advisory |
| https://paessler.freshdesk.com/en/support/solutio… | vendor-advisory |
| https://www.paessler.com/de/download/ | patch |
| https://www.paessler.com/prtg/prtg-network-monitor | product |
Impacted products
1 product
| Vendor | Product | Version | |
|---|---|---|---|
| Paessler GmbH | PRTG Network Monitor |
Affected:
0 , < 26.2.120.1449
(custom)
|
{
"containers": {
"adp": [
{
"metrics": [
{
"other": {
"content": {
"id": "CVE-2026-4638",
"options": [
{
"Exploitation": "none"
},
{
"Automatable": "no"
},
{
"Technical Impact": "partial"
}
],
"role": "CISA Coordinator",
"timestamp": "2026-09-24T12:13:17.297572Z",
"version": "2.0.3"
},
"type": "ssvc"
}
}
],
"providerMetadata": {
"dateUpdated": "2026-09-24T12:14:20.861Z",
"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"shortName": "CISA-ADP"
},
"title": "CISA ADP Vulnrichment"
}
],
"cna": {
"affected": [
{
"defaultStatus": "unaffected",
"product": "PRTG Network Monitor",
"vendor": "Paessler GmbH",
"versions": [
{
"lessThan": "26.2.120.1449",
"status": "affected",
"version": "0",
"versionType": "custom"
}
]
}
],
"credits": [
{
"lang": "en",
"type": "finder",
"value": "J. Kruchem, SEC Consult Vulnerability Lab"
},
{
"lang": "en",
"type": "finder",
"value": "S. Michlits, SEC Consult Vulnerability Lab"
}
],
"descriptions": [
{
"lang": "en",
"supportingMedia": [
{
"base64": false,
"type": "text/html",
"value": "\u003cdiv\u003e\u003cspan\u003ePRTG 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 \u0027Type mismatch\u0027 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.\u0026nbsp;\u003c/span\u003e\u003c/div\u003e\u003cdiv\u003e\u003cspan\u003e\u003cbr\u003e\u003c/span\u003e\u003c/div\u003e\u003cdiv\u003e\u003cspan\u003eAny 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\u0027s error output.\u003c/span\u003e\u003c/div\u003e"
}
],
"value": "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 \u0027Type mismatch\u0027 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.\u00a0\n\n\n\n\nAny 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\u0027s error output."
}
],
"impacts": [
{
"capecId": "CAPEC-54",
"descriptions": [
{
"lang": "en",
"value": "CAPEC-54 Query System for Information"
}
]
}
],
"metrics": [
{
"cvssV4_0": {
"Automatable": "NOT_DEFINED",
"Recovery": "NOT_DEFINED",
"Safety": "NOT_DEFINED",
"attackComplexity": "LOW",
"attackRequirements": "NONE",
"attackVector": "NETWORK",
"baseScore": 7.1,
"baseSeverity": "HIGH",
"exploitMaturity": "NOT_DEFINED",
"privilegesRequired": "LOW",
"providerUrgency": "NOT_DEFINED",
"subAvailabilityImpact": "NONE",
"subConfidentialityImpact": "NONE",
"subIntegrityImpact": "NONE",
"userInteraction": "NONE",
"valueDensity": "NOT_DEFINED",
"vectorString": "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",
"version": "4.0",
"vulnAvailabilityImpact": "NONE",
"vulnConfidentialityImpact": "HIGH",
"vulnIntegrityImpact": "NONE",
"vulnerabilityResponseEffort": "NOT_DEFINED"
},
"format": "CVSS",
"scenarios": [
{
"lang": "en",
"value": "GENERAL"
}
]
}
],
"problemTypes": [
{
"descriptions": [
{
"cweId": "CWE-209",
"description": "CWE-209 Generation of error message containing sensitive information",
"lang": "en",
"type": "CWE"
}
]
}
],
"providerMetadata": {
"dateUpdated": "2026-09-24T10:57:54.203Z",
"orgId": "551230f0-3615-47bd-b7cc-93e92e730bbf",
"shortName": "SEC-VLab"
},
"references": [
{
"tags": [
"third-party-advisory"
],
"url": "https://r.sec-consult.com/paessler"
},
{
"tags": [
"vendor-advisory"
],
"url": "https://paessler.freshdesk.com/en/support/solutions/articles/76000088640"
},
{
"tags": [
"patch"
],
"url": "https://www.paessler.com/de/download/"
},
{
"tags": [
"product"
],
"url": "https://www.paessler.com/prtg/prtg-network-monitor"
}
],
"solutions": [
{
"lang": "en",
"supportingMedia": [
{
"base64": false,
"type": "text/html",
"value": "Upgrade to Paessler PRTG Network Monitor version 26.2.120.1449 or later."
}
],
"value": "Upgrade to Paessler PRTG Network Monitor version 26.2.120.1449 or later."
}
],
"source": {
"discovery": "EXTERNAL"
},
"title": "Plaintext Password Disclosure via VBScript Sensor Error Message in Paessler PRTG Network Monitor",
"x_generator": {
"engine": "Vulnogram 1.0.5"
}
}
},
"cveMetadata": {
"assignerOrgId": "551230f0-3615-47bd-b7cc-93e92e730bbf",
"assignerShortName": "SEC-VLab",
"cveId": "CVE-2026-4638",
"datePublished": "2026-09-24T10:57:54.203Z",
"dateReserved": "2026-03-23T10:32:11.997Z",
"dateUpdated": "2026-09-24T12:14:20.861Z",
"state": "PUBLISHED"
},
"dataType": "CVE_RECORD",
"dataVersion": "5.2"
}
CVE-2026-4637 (GCVE-0-2026-4637)
Vulnerability from cvelistv5 – Published: 2026-09-24 10:05 – Updated: 2026-09-24 12:20
VLAI
EPSS
VEX
Title
Reflected Cross-Site Scripting via URL Path in Paessler PRTG Network Monitor
Summary
Paessler PRTG Network Monitor before version 26.2.120.1449 is affected by a reflected Cross-Site Scripting (XSS) vulnerability. When a request is made for a non-existent resource ending in \".htm\", the web interface returns an HTTP 403 \"Forbidden Path\" error page that echoes the requested URL path into the HTML response body without proper output encoding or sanitization.
An unauthenticated, remote attacker can craft a URL containing an HTML/JavaScript payload in the path (e.g. https:////welcome.htm) and, once a victim with an active PRTG session opens the crafted link, execute arbitrary JavaScript in the security context of the PRTG web interface. Because the PRTG session cookie is not protected with the HttpOnly attribute, successful exploitation allows the attacker to read and exfiltrate the victim's session cookie, potentially leading to session hijacking.
Severity
SSVC
Exploitation: poc
Automatable: yes
Technical Impact: partial
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2026-09-24 12:19 UTC
CWE
- CWE-79 - Improper neutralization of input during web page generation ('cross-site scripting')
Assigner
References
5 references
| URL | Tags |
|---|---|
| https://paessler.freshdesk.com/en/support/solutio… | vendor-advisory |
| https://www.paessler.com/de/download/ | patch |
| https://www.paessler.com/prtg/prtg-network-monitor | product |
| https://r.sec-consult.com/paessler | third-party-advisory |
| https://sec-consult.com/vulnerability-lab/advisor… | exploit |
Impacted products
1 product
| Vendor | Product | Version | |
|---|---|---|---|
| Paessler GmbH | PRTG Network Monitor |
Affected:
0 , < 26.2.120.1449
(custom)
|
{
"containers": {
"adp": [
{
"metrics": [
{
"other": {
"content": {
"id": "CVE-2026-4637",
"options": [
{
"Exploitation": "poc"
},
{
"Automatable": "yes"
},
{
"Technical Impact": "partial"
}
],
"role": "CISA Coordinator",
"timestamp": "2026-09-24T12:19:37.419469Z",
"version": "2.0.3"
},
"type": "ssvc"
}
}
],
"providerMetadata": {
"dateUpdated": "2026-09-24T12:20:41.854Z",
"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"shortName": "CISA-ADP"
},
"references": [
{
"tags": [
"exploit"
],
"url": "https://sec-consult.com/vulnerability-lab/advisory/multiple-vulnerabilities-in-paessler-prtg-network-monitor/"
}
],
"title": "CISA ADP Vulnrichment"
}
],
"cna": {
"affected": [
{
"defaultStatus": "unaffected",
"product": "PRTG Network Monitor",
"vendor": "Paessler GmbH",
"versions": [
{
"lessThan": "26.2.120.1449",
"status": "affected",
"version": "0",
"versionType": "custom"
}
]
}
],
"credits": [
{
"lang": "en",
"type": "finder",
"value": "J. Kruchem, SEC Consult Vulnerability Lab"
},
{
"lang": "en",
"type": "finder",
"value": "S. Michlits, SEC Consult Vulnerability Lab"
}
],
"descriptions": [
{
"lang": "en",
"supportingMedia": [
{
"base64": false,
"type": "text/html",
"value": "\u003cdiv\u003e\u003cspan\u003ePaessler PRTG Network Monitor before version 26.2.120.1449 is affected by a reflected Cross-Site Scripting (XSS) vulnerability. When a request is made for a non-existent resource ending in \\\".htm\\\", the web interface returns an HTTP 403 \\\"Forbidden Path\\\" error page that echoes the requested URL path into the HTML response body without proper output encoding or sanitization.\u003c/span\u003e\u003c/div\u003e\u003cdiv\u003e\u003cspan\u003e\u003cbr\u003e\u003c/span\u003e\u003c/div\u003e\u003cdiv\u003eAn unauthenticated, remote attacker can craft a URL containing an HTML/JavaScript payload in the path (e.g. https:////welcome.htm) and, once a victim with an active PRTG session opens the crafted link, execute arbitrary JavaScript in the security context of the PRTG web interface. Because the PRTG session cookie is not protected with the HttpOnly attribute, successful exploitation allows the attacker to read and exfiltrate the victim\u0027s session cookie, potentially leading to session hijacking.\u003c/div\u003e"
}
],
"value": "Paessler PRTG Network Monitor before version 26.2.120.1449 is affected by a reflected Cross-Site Scripting (XSS) vulnerability. When a request is made for a non-existent resource ending in \\\".htm\\\", the web interface returns an HTTP 403 \\\"Forbidden Path\\\" error page that echoes the requested URL path into the HTML response body without proper output encoding or sanitization.\n\n\n\n\nAn unauthenticated, remote attacker can craft a URL containing an HTML/JavaScript payload in the path (e.g. https:////welcome.htm) and, once a victim with an active PRTG session opens the crafted link, execute arbitrary JavaScript in the security context of the PRTG web interface. Because the PRTG session cookie is not protected with the HttpOnly attribute, successful exploitation allows the attacker to read and exfiltrate the victim\u0027s session cookie, potentially leading to session hijacking."
}
],
"impacts": [
{
"capecId": "CAPEC-591",
"descriptions": [
{
"lang": "en",
"value": "CAPEC-591 Reflected XSS"
}
]
}
],
"metrics": [
{
"cvssV4_0": {
"Automatable": "NOT_DEFINED",
"Recovery": "NOT_DEFINED",
"Safety": "NOT_DEFINED",
"attackComplexity": "LOW",
"attackRequirements": "NONE",
"attackVector": "NETWORK",
"baseScore": 5.1,
"baseSeverity": "MEDIUM",
"exploitMaturity": "NOT_DEFINED",
"privilegesRequired": "NONE",
"providerUrgency": "NOT_DEFINED",
"subAvailabilityImpact": "NONE",
"subConfidentialityImpact": "LOW",
"subIntegrityImpact": "LOW",
"userInteraction": "ACTIVE",
"valueDensity": "NOT_DEFINED",
"vectorString": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N",
"version": "4.0",
"vulnAvailabilityImpact": "NONE",
"vulnConfidentialityImpact": "NONE",
"vulnIntegrityImpact": "NONE",
"vulnerabilityResponseEffort": "NOT_DEFINED"
},
"format": "CVSS",
"scenarios": [
{
"lang": "en",
"value": "GENERAL"
}
]
}
],
"problemTypes": [
{
"descriptions": [
{
"cweId": "CWE-79",
"description": "CWE-79 Improper neutralization of input during web page generation (\u0027cross-site scripting\u0027)",
"lang": "en",
"type": "CWE"
}
]
}
],
"providerMetadata": {
"dateUpdated": "2026-09-24T10:05:06.998Z",
"orgId": "551230f0-3615-47bd-b7cc-93e92e730bbf",
"shortName": "SEC-VLab"
},
"references": [
{
"tags": [
"vendor-advisory"
],
"url": "https://paessler.freshdesk.com/en/support/solutions/articles/76000088640"
},
{
"tags": [
"patch"
],
"url": "https://www.paessler.com/de/download/"
},
{
"tags": [
"product"
],
"url": "https://www.paessler.com/prtg/prtg-network-monitor"
},
{
"tags": [
"third-party-advisory"
],
"url": "https://r.sec-consult.com/paessler"
}
],
"solutions": [
{
"lang": "en",
"supportingMedia": [
{
"base64": false,
"type": "text/html",
"value": "Upgrade to Paessler PRTG Network Monitor version 26.2.120.1449 or later."
}
],
"value": "Upgrade to Paessler PRTG Network Monitor version 26.2.120.1449 or later."
}
],
"source": {
"discovery": "EXTERNAL"
},
"title": "Reflected Cross-Site Scripting via URL Path in Paessler PRTG Network Monitor",
"x_generator": {
"engine": "Vulnogram 1.0.5"
}
}
},
"cveMetadata": {
"assignerOrgId": "551230f0-3615-47bd-b7cc-93e92e730bbf",
"assignerShortName": "SEC-VLab",
"cveId": "CVE-2026-4637",
"datePublished": "2026-09-24T10:05:06.998Z",
"dateReserved": "2026-03-23T10:31:35.511Z",
"dateUpdated": "2026-09-24T12:20:41.854Z",
"state": "PUBLISHED"
},
"dataType": "CVE_RECORD",
"dataVersion": "5.2"
}