PT-2026-31798 · Juniper Networks · Junos+1

Published

2026-04-09

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Updated

2026-04-09

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CVE-2026-33774

CVSS v3.1

6.5

Medium

VectorAV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N
Name of the Vulnerable Software and Affected Versions Juniper Networks Junos OS on MX Series versions prior to 23.2R2-S6 Juniper Networks Junos OS on MX Series versions 23.4 before 23.4R2-S7 Juniper Networks Junos OS on MX Series versions 24.2 before 24.2R2 Juniper Networks Junos OS on MX Series versions 24.4 before 24.4R2
Description A flaw exists in the packet forwarding engine (pfe) of Juniper Networks Junos OS on MX Series that allows an unauthenticated, network-based attacker to bypass configured firewall filters and access the control-plane of the device. This occurs when firewall filters are applied on a loopback interface lo0.n (where n is a non-0 number) and that loopback interface is in the global VRF / default routing-instance. The issue is observed when the firewall counter for the filter does not show any matches.
Recommendations Update to Junos OS version 23.2R2-S6 or later. Update to Junos OS version 23.4R2-S7 or later. Update to Junos OS version 24.2R2 or later. Update to Junos OS version 24.4R2 or later.

Fix

Improper Check for Exceptional Conditions

Weakness Enumeration

CWE-754

Related Identifiers

CVE-2026-33774

Affected Products

Junos
Mx Series