Home/CVE/An Incorrect Initialization of Resource vulnerability in the packet forwarding engine (pfe) of Juniper Networks Junos OS
CVE

CVE-2026-33773

An Incorrect Initialization of Resource vulnerability in the packet forwarding engine (pfe) of Juniper Networks Junos OS

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.

MEDIUM · CVSS 5.8 EPSS 0.00051
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  • SSVC automatable: yes - attacks can be scripted at scale
Sigma rules0 YARA rules0
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Affected Products & Versions

1
juniper junosall versions
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Scoring & Timeline

5.8
MEDIUM · CVSS v3.1 · sirt@juniper.net
View on NVD
Attack Vector
Network Adjacent Local Physical
Attack Complexity
Low High
Privileges Required
None Low High
User Interaction
None Required
Scope
Unchanged Changed
Confidentiality
None Low High
Integrity
None Low High
Availability
None Low High
Published to NVD09 Apr 2026 · 10:16 PM
CVSS VectorCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:N
SSVC triage · cisa-vulnrichment
Exploitation
none
Automatable
yes
Technical impact
partial
SSVC asks the questions that actually drive patch urgency: is it being exploited, can attacks be automated, and how total is the impact.
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References & Sources

1
Source URLs (vendor pages, mailing lists, write-ups). Exploit/PoC links are in their own section above to avoid duplication.
https://kb.juniper.net/JSA107815MitigationVendor Advisory
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