An Unchecked Input for Loop Condition vulnerability in the Packet Forwarding Engine (pfe) of Juniper Networks Junos OS on MX Series allows an unauthenticated, adjacent attacker to cause a Denial-of-Service (DoS).Micro-BFD session flaps generate respective up/down events which are queued by PFEMAN for processing. Especially in a Virtual-Chassis (VC) scenario with locality‑bias configured, processing takes a significant amount of time for each event. If these sessions keep flapping, new events are constantly added, and in turn PFEMAN never completes processing these events. This results in the PFEMAN watchdog timer expiring, which causes the FPC to crash and restart, representing a complete service outage. This issue only affects MX series FPCs up to and including MPC9, and LC2101/2103 and LC480. It does not affect MPC10/11, LC4800/9600, and MX304. This issue affects Junos OS on MX Series: * all versions before 23.2R2-S7, * 23.4 versions before 23.4R2-S8, * 24.2 versions before 24.2R2-S4, * 24.4 versions before 24.4R2-S3, * 25.2 versions before 25.2R2.
This vulnerability carries a MEDIUM severity rating with a CVSS v3.1 score of 6.5, indicating it requires adjacent network access with relatively low complexity without requiring user interaction and does not require pre-existing privileges . The vulnerability impacts and availability (service disruption) for affected systems. Impacting 25 products from juniper, from juniper, from juniper and 22 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.
2026-07-09T21:16:55.163
2026-08-26T16:56:41.773
Analyzed
CVSSv3.1: 6.5 (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 | 23.2 | 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 | 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 | 24.2 | 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 | 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 | lc2101 | - | No |
| Hardware | juniper | lc2103 | - | No |
| Hardware | juniper | lc4800 | - | No |
| Hardware | juniper | mpc1 | - | No |
| Hardware | juniper | mpc1_q | - | No |
| Hardware | juniper | mpc1e | - | No |
| Hardware | juniper | mpc1e_q | - | No |
| Hardware | juniper | mpc2 | - | No |
| Hardware | juniper | mpc2_eq | - | No |
| Hardware | juniper | mpc2_q | - | No |
| Hardware | juniper | mpc2e | - | No |
| Hardware | juniper | mpc2e_eq | - | No |
| Hardware | juniper | mpc2e_ng | - | No |
| Hardware | juniper | mpc2e_ng_q | - | No |
| Hardware | juniper | mpc2e_p | - | No |
| Hardware | juniper | mpc2e_q | - | No |
| Hardware | juniper | mpc3e | - | No |
| Hardware | juniper | mpc3e-3d-ng | - | No |
| Hardware | juniper | mpc3e-3d-ng-q | - | No |
| Hardware | juniper | mpc6e | - | No |
| Hardware | juniper | mpc7e-10g | - | No |
| Hardware | juniper | mpc7e-mrate | - | No |
| Hardware | juniper | mpc8e | - | No |
| Hardware | juniper | mpc9e | - | 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.