CVE-2026-21902
Junos OS Evolved: PTX Series: A vulnerability allows a unauthenticated, network-based attacker to execute code as root
An Incorrect Permission Assignment for Critical Resource vulnerability in the On-Box Anomaly detection framework of Juniper Networks Junos OS Evolved on PTX Series allows an unauthenticated, network-based attacker to execute code as root.
The On-Box Anomaly detection framework should only be reachable by other internal processes over the internal routing instance, but not over an externally exposed port. With the ability to access and manipulate the service to execute code as root a remote attacker can take complete control of the device. Please note that this service is enabled by default as no specific configuration is required.
This issue affects Junos OS Evolved on PTX Series:
- 25.4 versions before 25.4R1-S1-EVO, 25.4R2-EVO.
This issue does not affect Junos OS Evolved versions before 25.4R1-EVO.
This issue does not affect Junos OS.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- None
What an attacker can affect
- Confidentiality
- High
- Integrity
- High
- Availability
- High
Exploit likelihood
What each source reports
CVE List Score used
Junos OS Evolved: PTX Series: A vulnerability allows a unauthenticated, network-based attacker to execute code as root
An Incorrect Permission Assignment for Critical Resource vulnerability in the On-Box Anomaly detection framework of Juniper Networks Junos OS Evolved on PTX Series allows an unauthenticated, network-based attacker to execute code as root.
The On-Box Anomaly detection framework should only be reachable by other internal processes over the internal routing instance, but not over an externally exposed port. With the ability to access and manipulate the service to execute code as root a remote attacker can take complete control of the device. Please note that this service is enabled by default as no specific configuration is required.
This issue affects Junos OS Evolved on PTX Series:
- 25.4 versions before 25.4R1-S1-EVO, 25.4R2-EVO.
This issue does not affect Junos OS Evolved versions before 25.4R1-EVO.
This issue does not affect Junos OS.
- Record
CVE-2026-21902- CVSS 4.0
- 9.3 Critical
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:L/AU:Y/R:U/RE:M/U:Red - CVSS 3.1
- 9.8 Critical
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H - Weakness
- CWE-732
- Updated
- 2026-11-02
EUVDEUVD-2026-8693
An Incorrect Permission Assignment for Critical Resource vulnerability in the On-Box Anomaly detection framework of Juniper Networks Junos OS Evolved on PTX Series allows an unauthenticated, network-based attacker to execute code as root.
The On-Box Anomaly detection framework should only be reachable by other internal processes over the internal routing instance, but not over an externally exposed port. With the ability to access and manipulate the service to execute code as root a remote attacker can take complete control of the device. Please note that this service is enabled by default as no specific configuration is required.
This issue affects Junos OS Evolved on PTX Series:
- 25.4 versions before 25.4R1-S1-EVO, 25.4R2-EVO.
This issue does not affect Junos OS Evolved versions before 25.4R1-EVO.
This issue does not affect Junos OS.
- Record
EUVD-2026-8693- CVSS 4.0
- 9.3 Critical
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:L/AU:Y/R:U/RE:M/U:Red - Updated
- 2026-11-02
GitHub AdvisoriesGHSA-5w57-gjvc-whwc
An Incorrect Permission Assignment for Critical Resource vulnerability in the On-Box Anomaly...
An Incorrect Permission Assignment for Critical Resource vulnerability in the On-Box Anomaly detection framework of Juniper Networks Junos OS Evolved on PTX Series allows an unauthenticated, network-based attacker to execute code as root.
The On-Box Anomaly detection framework should only be reachable by other internal processes over the internal routing instance, but not over an externally exposed port. With the ability to access and manipulate the service to execute code as root a remote attacker can take complete control of the device. Please note that this service is enabled by default as no specific configuration is required.
This issue affects Junos OS Evolved on PTX Series:
- 25.4 versions before 25.4R1-S1-EVO, 25.4R2-EVO.
This issue does not affect Junos OS Evolved versions before 25.4R1-EVO.
This issue does not affect Junos OS.
- Record
GHSA-5w57-gjvc-whwc- CVSS 4.0
- 9.3 Critical
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:L/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:Y/R:U/V:X/RE:M/U:Red - CVSS 3.1
- 9.8 Critical
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H - Weakness
- CWE-732
- Updated
- 2026-11-02
NVD
An Incorrect Permission Assignment for Critical Resource vulnerability in the On-Box Anomaly detection framework of Juniper Networks Junos OS Evolved on PTX Series allows an unauthenticated, network-based attacker to execute code as root.
The On-Box Anomaly detection framework should only be reachable by other internal processes over the internal routing instance, but not over an externally exposed port. With the ability to access and manipulate the service to execute code as root a remote attacker can take complete control of the device. Please note that this service is enabled by default as no specific configuration is required.
This issue affects Junos OS Evolved on PTX Series:
- 25.4 versions before 25.4R1-S1-EVO, 25.4R2-EVO.
This issue does not affect Junos OS Evolved versions before 25.4R1-EVO.
This issue does not affect Junos OS.
- Record
CVE-2026-21902- CVSS 4.0
- 9.3 Critical
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:L/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:Y/R:U/V:X/RE:M/U:Red - CVSS 3.1
- 9.8 Critical
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H - Weakness
- CWE-732
- Updated
- 2026-11-02
Affected products
Public exploits
Links only. Every CVE stores no exploit code.
| Source | Link | Date |
|---|---|---|
| PoC in GitHub | watchtowrlabs/watchTowr-vs-JunosEvolved-CVE-2026-21902 | 2026-02-28 |
History
| Recorded | Changed | Sources |
|---|---|---|
| first indexed | CVE List, EUVD, GitHub Advisories, NVD, PoC in GitHub |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2026-21902 is a critical vulnerability (CVSS 9.3) in Juniper Junos Os Evolved, published February 25, 2026. Public exploit code exists. EPSS puts the chance of exploitation in the next 30 days at 18.5%, the 97th percentile. No source names a fixed version.