High (7.5) in juniper junos. EPSS 0.4% chance of exploitation in the next 30 days.
An Exposure of Resource to Wrong Sphere vulnerability in the Packet Forwarding Engine (PFE) of Juniper Networks Junos OS on MX Series allows an unauthenticated, network-based attacker to bypass the intended access restrictions.
In an Abstracted Fabric (AF) scenario if routing-instances (RI) are configured, specific valid traffic destined to the device can bypass the configured lo0 firewall filters as it's received in the wrong RI context.
This issue affects Juniper Networks Junos OS on MX Series:
* All versions earlier than 20.4R3-S9;
* 21.2 versions earlier than 21.2R3-S3;
* 21.4 versions earlier than 21.4R3-S5;
* 22.1 versions earlier than 22.1R3;
* 22.2 versions earlier than 22.2R3;
* 22.3 versions earlier than 22.3R2.
Severity
CVSS 3.1
7.5 high
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
EPSS
0.4% chance of exploitation in the next 30 days; higher than 31% of CVEs (scores of 2026-10-31)