Skip to content
OpenAdvisories
Medium · 6.5 CVE-2026-33781

Junos OS: EX Series, QFX Series: In a VXLAN scenario when specific control protocol packets are received, memory leaks and eventually no traffic is passed

Published Apr 9, 2026 · Updated Apr 10, 2026 · Assigned by juniper

Description

An Improper Check for Unusual or Exceptional Conditions vulnerability in the packet forwarding engine (pfe) of Juniper Networks Junos OS on specific EX and QFX Series devices allow an unauthenticated, adjacent attacker to cause a complete Denial of Service (DoS).

On EX4k, and QFX5k platforms configured as service-provider edge devices, if L2PT is enabled on the UNI and VSTP is enabled on NNI in VXLAN scenarios, receiving VSTP BPDUs on UNI leads to packet buffer allocation failures, resulting in the device to not pass traffic anymore until it is manually recovered with a restart.This issue affects Junos OS:

* 24.4 releases before 24.4R2,
* 25.2 releases before 25.2R1-S1, 25.2R2.

This issue does not affect Junos OS releases before 24.4R1.

Affected products

VendorProductAffectedFixed
Juniper Networks Junos OS 24.4 – < 24.4R2, 25.2 – < 25.2R1-S1, 25.2R2 24.4R2

Advisories 1

References