Junos OS Evolved: PTX Series: A vulnerability allows a unauthenticated, network-based attacker to execute code as root
Summary
| CVE | CVE-2026-21902 |
|---|---|
| State | PUBLISHED |
| Assigner | juniper |
| Source Priority | CVE Program / NVD first with legacy fallback |
| Published | 2026-02-25 18:23:40 UTC |
| Updated | 2026-03-30 15:16:05 UTC |
| Description | 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. |
Risk And Classification
Primary CVSS: v4.0 9.3 CRITICAL from [email protected]
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
EPSS: 0.002880000 probability, percentile 0.521720000 (date 2026-04-01)
Problem Types: CWE-732 | CWE-732 CWE-732 Incorrect Permission Assignment for Critical Resource
| Version | Source | Type | Score | Severity | Vector |
|---|---|---|---|---|---|
| 4.0 | [email protected] | Secondary | 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/C... |
| 4.0 | CNA | CVSS | 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/... |
| 3.1 | [email protected] | Secondary | 9.8 | CRITICAL | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H |
| 3.1 | CNA | CVSS | 9.8 | CRITICAL | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H |
CVSS v4.0 Breakdown
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 v3.1 Breakdown
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
NVD Known Affected Configurations (CPE 2.3)
| Type | Vendor | Product | Version | Update | Edition | Language |
|---|---|---|---|---|---|---|
| Operating System | Juniper | Junos Os Evolved | 25.4 | r1 | All | All |
| Hardware | Juniper | Ptx10001-36mr | - | All | All | All |
| Hardware | Juniper | Ptx10002-36qdd | - | All | All | All |
| Hardware | Juniper | Ptx10003 | - | All | All | All |
| Hardware | Juniper | Ptx10004 | - | All | All | All |
| Hardware | Juniper | Ptx10008 | - | All | All | All |
| Hardware | Juniper | Ptx10016 | - | All | All | All |
Vendor Declared Affected Products
| Source | Vendor | Product | Version | Platforms |
|---|---|---|---|---|
| CNA | Juniper Networks | Junos OS Evolved | affected 25.4 25.4R1-S1-EVO, 25.4R2-EVO semver | PTX Series |
| CNA | Juniper Networks | Junos OS Evolved | unaffected 25.4R1-EVO semver | PTX Series |
References
| Reference | Source | Link | Tags |
|---|---|---|---|
| kb.juniper.net/JSA107128 | [email protected] | kb.juniper.net | Mitigation, Vendor Advisory |
| github.com/watchtowrlabs/watchTowr-vs-JunosEvolved-CVE-2026-21902/blob/m... | 134c704f-9b21-4f2e-91b3-4a467353bcc0 | github.com | Product |
| supportportal.juniper.net/JSA107128 | [email protected] | supportportal.juniper.net | Mitigation, Vendor Advisory |
| CVE Program record | CVE.ORG | www.cve.org | canonical |
| NVD vulnerability detail | NVD | nvd.nist.gov | canonical, analysis |
Additional Advisory Data
Solutions
CNA: The following software releases have been updated to resolve this specific issue: 25.4R1-S1-EVO, 25.4R2-EVO*, 26.2R1-EVO*, and all subsequent releases. * Future Release
Workarounds
CNA: To reduce the risk of exploitation of this issue, use access lists or firewall filters to limit access to only trusted networks and hosts. Please ensure such filters only permit explicitly required connections and block all others. Also this service can be disabled by 'request pfe anomalies disable'.
Exploits
CNA: Juniper SIRT is not aware of any malicious exploitation of this vulnerability.