Junos OS Evolved: A port which has been inadvertently exposed can be reached by an attacker
Summary
| CVE | CVE-2026-33803 |
|---|---|
| State | PUBLISHED |
| Assigner | juniper |
| Source Priority | CVE Program / NVD first with legacy fallback |
| Published | 2026-07-09 22:17:03 UTC |
| Updated | 2026-07-13 20:59:26 UTC |
| Description | An Improper Restriction of Communication Channel to Intended Endpoints vulnerability in Juniper Networks Junos OS Evolved allows an unauthenticated, network-based attacker to cause a limited information disclosure and availability impact to the device. Due to a wrong initialization, a process which should only be able to communicate internally within the device can be reached over the network via an open port. This leads to a device being inadvertently exposed and increased CPU cycles spent processing ingress packets. This issue affects Junos OS Evolved: * all versions before 23.2R2-S7-EVO, * 23.4 versions before 23.4R2-S8-EVO, * 24.2 versions before 24.2R2-S5-EVO, * 24.4 versions before 24.4R2-S4-EVO, * 25.2 versions before 25.2R2-S1-EVO, * 25.4 versions before 25.4R1-S2-EVO. |
Risk And Classification
Primary CVSS: v4.0 6.9 MEDIUM from [email protected]
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:L/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:Y/R:U/V:X/RE:M/U:X
EPSS: 0.003540000 probability, percentile 0.274990000 (date 2026-07-12)
Problem Types: CWE-923 | CWE-923 CWE-923 Improper Restriction of Communication Channel to Intended Endpoints
| Version | Source | Type | Score | Severity | Vector |
|---|---|---|---|---|---|
| 4.0 | [email protected] | Secondary | 6.9 | MEDIUM | CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:L/SC:N/SI:N/SA:N/E:X/C... |
| 4.0 | CNA | CVSS | 6.9 | MEDIUM | CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:L/SC:N/SI:N/SA:N/AU:Y/... |
| 3.1 | [email protected] | Secondary | 6.5 | MEDIUM | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:L |
| 3.1 | CNA | CVSS | 6.5 | MEDIUM | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:L |
CVSS v4.0 Breakdown
Attack Vector
NetworkAttack Complexity
LowAttack Requirements
NonePrivileges Required
NoneUser Interaction
NoneConfidentiality
LowIntegrity
NoneAvailability
LowSub Conf.
NoneSub Integrity
NoneSub Availability
NoneCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:L/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:Y/R:U/V:X/RE:M/U:X
CVSS v3.1 Breakdown
Attack Vector
NetworkAttack Complexity
LowPrivileges Required
NoneUser Interaction
NoneScope
UnchangedConfidentiality
LowIntegrity
NoneAvailability
LowCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:L
NVD Known Affected Configurations (CPE 2.3)
| Type | Vendor | Product | Version | Update | Edition | Language |
|---|---|---|---|---|---|---|
| Operating System | Juniper | Junos Os Evolved | All | All | All | All |
| Operating System | Juniper | Junos Os Evolved | 23.2 | - | All | All |
| Operating System | Juniper | Junos Os Evolved | 23.2 | r1 | All | All |
| Operating System | Juniper | Junos Os Evolved | 23.2 | r1-s1 | All | All |
| Operating System | Juniper | Junos Os Evolved | 23.2 | r1-s2 | All | All |
| Operating System | Juniper | Junos Os Evolved | 23.2 | r2 | All | All |
| Operating System | Juniper | Junos Os Evolved | 23.2 | r2-s1 | All | All |
| Operating System | Juniper | Junos Os Evolved | 23.2 | r2-s2 | All | All |
| Operating System | Juniper | Junos Os Evolved | 23.2 | r2-s3 | All | All |
| Operating System | Juniper | Junos Os Evolved | 23.2 | r2-s4 | All | All |
| Operating System | Juniper | Junos Os Evolved | 23.2 | r2-s5 | All | All |
| Operating System | Juniper | Junos Os Evolved | 23.2 | r2-s6 | All | All |
| Operating System | Juniper | Junos Os Evolved | 23.4 | - | All | All |
| Operating System | Juniper | Junos Os Evolved | 23.4 | r1 | All | All |
| Operating System | Juniper | Junos Os Evolved | 23.4 | r1-s1 | All | All |
| Operating System | Juniper | Junos Os Evolved | 23.4 | r1-s2 | All | All |
| Operating System | Juniper | Junos Os Evolved | 23.4 | r2 | All | All |
| Operating System | Juniper | Junos Os Evolved | 23.4 | r2-s1 | All | All |
| Operating System | Juniper | Junos Os Evolved | 23.4 | r2-s2 | All | All |
| Operating System | Juniper | Junos Os Evolved | 23.4 | r2-s3 | All | All |
| Operating System | Juniper | Junos Os Evolved | 23.4 | r2-s4 | All | All |
| Operating System | Juniper | Junos Os Evolved | 23.4 | r2-s5 | All | All |
| Operating System | Juniper | Junos Os Evolved | 23.4 | r2-s6 | All | All |
| Operating System | Juniper | Junos Os Evolved | 23.4 | r2-s7 | All | All |
| Operating System | Juniper | Junos Os Evolved | 24.2 | - | All | All |
| Operating System | Juniper | Junos Os Evolved | 24.2 | r1 | All | All |
| Operating System | Juniper | Junos Os Evolved | 24.2 | r1-s2 | All | All |
| Operating System | Juniper | Junos Os Evolved | 24.2 | r2 | All | All |
| Operating System | Juniper | Junos Os Evolved | 24.2 | r2-s1 | All | All |
| Operating System | Juniper | Junos Os Evolved | 24.2 | r2-s2 | All | All |
| Operating System | Juniper | Junos Os Evolved | 24.2 | r2-s3 | All | All |
| Operating System | Juniper | Junos Os Evolved | 24.2 | r2-s4 | All | All |
| Operating System | Juniper | Junos Os Evolved | 24.4 | - | All | All |
| Operating System | Juniper | Junos Os Evolved | 24.4 | r1 | All | All |
| Operating System | Juniper | Junos Os Evolved | 24.4 | r1-s2 | All | All |
| Operating System | Juniper | Junos Os Evolved | 24.4 | r1-s3 | All | All |
| Operating System | Juniper | Junos Os Evolved | 24.4 | r2 | All | All |
| Operating System | Juniper | Junos Os Evolved | 24.4 | r2-s1 | All | All |
| Operating System | Juniper | Junos Os Evolved | 24.4 | r2-s2 | All | All |
| Operating System | Juniper | Junos Os Evolved | 24.4 | r2-s3 | All | All |
| Operating System | Juniper | Junos Os Evolved | 25.2 | - | All | All |
| Operating System | Juniper | Junos Os Evolved | 25.2 | r1 | All | All |
| Operating System | Juniper | Junos Os Evolved | 25.2 | r1-s1 | All | All |
| Operating System | Juniper | Junos Os Evolved | 25.2 | r1-s2 | All | All |
| Operating System | Juniper | Junos Os Evolved | 25.2 | r2 | All | All |
| Operating System | Juniper | Junos Os Evolved | 25.4 | - | All | All |
| Operating System | Juniper | Junos Os Evolved | 25.4 | r1 | All | All |
| Operating System | Juniper | Junos Os Evolved | 25.4 | r1-s1 | All | All |
Vendor Declared Affected Products
| Source | Vendor | Product | Version | Platforms |
|---|---|---|---|---|
| CNA | Juniper Networks | Junos OS Evolved | affected 23.2R2-S7-EVO custom | Not specified |
| CNA | Juniper Networks | Junos OS Evolved | affected 23.4 23.4R2-S8-EVO custom | Not specified |
| CNA | Juniper Networks | Junos OS Evolved | affected 24.2 24.2R2-S5-EVO custom | Not specified |
| CNA | Juniper Networks | Junos OS Evolved | affected 24.4 24.4R2-S4-EVO custom | Not specified |
| CNA | Juniper Networks | Junos OS Evolved | affected 25.2 25.2R2-S1-EVO custom | Not specified |
| CNA | Juniper Networks | Junos OS Evolved | affected 25.4 25.4R1-S2-EVO custom | Not specified |
References
| Reference | Source | Link | Tags |
|---|---|---|---|
| supportportal.juniper.net/JSA110078 | [email protected] | supportportal.juniper.net | Vendor Advisory |
| CVE Program record | CVE.ORG | www.cve.org | canonical |
| NVD vulnerability detail | NVD | nvd.nist.gov | canonical, analysis |
No vendor comments have been submitted for this CVE.
Additional Advisory Data
Solutions
CNA: The following software releases have been updated to resolve this specific issue: Junos OS Evolved: 23.2R2-S7-EVO, 23.4R2-S8-EVO, 24.2R2-S5-EVO, 24.4R2-S4-EVO, 25.2R2-S1-EVO, 25.4R1-S2-EVO, 25.4R2-EVO, 26.2R1-EVO, and all subsequent releases.
Workarounds
CNA: There are no known workarounds for this issue. Please ensure that your control plane protection only explicitly permits access to ports intended to be reachable and only from authorized endpoints. All other traffic destined to the control plane should be disallowed.
Exploits
CNA: Juniper SIRT is not aware of any malicious exploitation of this vulnerability.
There are currently no legacy QID mappings associated with this CVE.