An Improper Check for Unusual or Exceptional Conditions vulnerability in the packet forwarding engine (PFE) of Juniper Networks Junos OS on MX Series allows adjacent subscribers to bypass configured firewall filters. On MX Series devices with MPC10/11, LC4800/9600, and MX304 with subscribers configured on static interfaces, ingress firewall filters are not enforced, so that neither protocol level nor upstream bandwidth limitation are in effect. This issue affects Junos OS on MX with MPC10/11, LC4800/9600/4802, and MX304: * 23.2 versions from 23.2R2-S1 before 23.2R2-S7, * 23.4 versions from 23.4R2 before 23.4R2-S7, * 24.2 versions before 24.2R2-S3, * 24.4 versions before 24.4R2-S2, * 25.2 versions before 25.2R2.
This vulnerability carries a MEDIUM severity rating with a CVSS v3.1 score of 4.7, indicating it requires adjacent network access with relatively low complexity without requiring user interaction and does not require pre-existing privileges . The vulnerability impacts limited integrity, for affected systems. Impacting 8 products from juniper, from juniper, from juniper and 5 others, organizations running these solutions should prioritize assessment and patching.
Reported in 2026, this vulnerability emerged during an era marked by increased sophistication in supply chain attacks, cloud infrastructure vulnerabilities, and software-as-a-service (SaaS) security challenges. Security practices during this period emphasized zero-trust architectures, container security, and API protection.
2026-07-09T22:17:08.827
2026-08-25T20:13:56.420
Analyzed
CVSSv3.1: 4.7 (MEDIUM)
| Type | Vendor | Product | Version/Range | Vulnerable? |
|---|---|---|---|---|
| Operating System | juniper | junos | 23.2 | Yes |
| Operating System | juniper | junos | 23.2 | Yes |
| Operating System | juniper | junos | 23.2 | Yes |
| Operating System | juniper | junos | 23.2 | Yes |
| Operating System | juniper | junos | 23.2 | Yes |
| Operating System | juniper | junos | 23.2 | Yes |
| Operating System | juniper | junos | 23.4 | Yes |
| Operating System | juniper | junos | 23.4 | Yes |
| Operating System | juniper | junos | 23.4 | Yes |
| Operating System | juniper | junos | 23.4 | Yes |
| Operating System | juniper | junos | 23.4 | Yes |
| Operating System | juniper | junos | 23.4 | Yes |
| Operating System | juniper | junos | 23.4 | Yes |
| Operating System | juniper | junos | 24.2 | Yes |
| Operating System | juniper | junos | 24.2 | Yes |
| Operating System | juniper | junos | 24.2 | Yes |
| Operating System | juniper | junos | 24.2 | Yes |
| Operating System | juniper | junos | 24.2 | Yes |
| Operating System | juniper | junos | 24.2 | Yes |
| Operating System | juniper | junos | 24.2 | Yes |
| Operating System | juniper | junos | 24.4 | Yes |
| Operating System | juniper | junos | 24.4 | Yes |
| Operating System | juniper | junos | 24.4 | Yes |
| Operating System | juniper | junos | 24.4 | Yes |
| Operating System | juniper | junos | 24.4 | Yes |
| Operating System | juniper | junos | 24.4 | Yes |
| Operating System | juniper | junos | 25.2 | Yes |
| Operating System | juniper | junos | 25.2 | Yes |
| Operating System | juniper | junos | 25.2 | Yes |
| Operating System | juniper | junos | 25.2 | Yes |
| Hardware | juniper | lc4800 | - | No |
| Hardware | juniper | lc4802 | - | No |
| Hardware | juniper | lc9600 | - | No |
| Hardware | juniper | mpc10e-10c | - | No |
| Hardware | juniper | mpc10e-15c | - | No |
| Hardware | juniper | mpc11 | - | No |
| Hardware | juniper | mx304 | - | No |
SecUtils normalizes and enriches National Vulnerability Database (NVD) records by standardizing vendor and product identifiers, aggregating vulnerability metadata from both NVD and MITRE sources, and providing structured context for security teams. For juniper's affected products, we extract Common Platform Enumeration (CPE) data, Common Weakness Enumeration (CWE) classifications, CVSS severity metrics, and reference data to enable rapid vulnerability prioritization and asset correlation. This record contains no exploit code, proof-of-concept instructions, or attack methodologies—only defensive intelligence necessary for patch management, risk assessment, and security operations.