Junos OS (SRX firewalls)
CVE-2026-33773: EX Series, QFX Series: If the same egress filter is configured on both an IRB and a physical interface one of those is not applied
An Incorrect Initialization of Resource vulnerability in the packet forwarding engine (pfe) of Juniper Networks Junos OS on specific EX Series and QFX Series device allows an unauthenticated, network-based attacker to cause an integrity impact to downstream networks.
Published
Automatic summary from the vendor's CVE record. We haven't written a full analysis of this vulnerability yet.
Affected and fixed versions
| Product / branch | Fixed in |
|---|---|
| Junos OS (EX Series, QFX Series) 23.4R2-S6 | 23.4R2-S7 or later |
| Junos OS (EX Series, QFX Series) 24.2R2-S3 | 24.2R2-S4 or later |
Always confirm against the vendor advisory, which lists every fixed hotfix.
What it is
An Incorrect Initialization of Resource vulnerability in the packet forwarding engine (pfe) of Juniper Networks Junos OS on specific EX Series and QFX Series device allows an unauthenticated, network-based attacker to cause an integrity impact to downstream networks.
When the same family inet or inet6 filter is applied on an IRB interface and on a physical interface as egress filter on EX4100, EX4400, EX4650 and QFX5120 devices, only one of the two filters will be applied, which can lead to traffic being sent out one of these interfaces which should have been blocked.
This issue affects Junos OS on EX Series and QFX Series: * 23.4 version 23.4R2-S6, * 24.2 version 24.2R2-S3.
No other Junos OS versions are affected.
Am I affected?
For a device to be affected the same filter needs to be applied as output to an IRB interface and a non-IRB interface as shown in the following example:
interfaces <interface1> unit <unit1> family inet/inet6 filter output <filter>
vlans <vlan_name> vlan-id <vlan#> vlans <vlan_name> l3-interface irb.<unit2>
interfaces <interface2> unit <unit3> family ethernet-switching vlan members <vlan_name>
interfaces irb unit <unit2> family inet/inet6 filter output <filter>
Workarounds
Two different workarounds are available:
- create the same filter but under a different name and apply that to one of the interfaces, so that each interface has a unique copy of the filter in question as shown in the following example:
user@host# copy ... <filter> to ... <filter2> user@host# set interfaces irb unit <unit2> family inet/inet6 filter output <filter2>
- configure the filter as "interface specific" by adding the keyword to the filter definition:
[ firewall family inet/inet6 filter <filter> interface-specific ]
which implicitly creates a copy of the original filter per applied interface.
Exploitation
Juniper SIRT is not aware of any malicious exploitation of this vulnerability.
Sources
KEV status, EPSS score and vendor data refreshed automatically, last on 13 Oct 2026.