CVE-2026-33781CWE-754

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

High · published April 9, 2026

CVSS v4.0
7.1
EPSS
0%
Percentile
18.0
In the wild
Unconfirmed
What it is

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.

The record
Technical detail
CVSS v4.0
7.1 · HIGH
Vector
CVSS:4.0/AV:A/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:L/AU:Y/RE:M
EPSS
0.00269 · 18.0th percentile
Weakness
CWE-754 · Improper Check for Unusual or Exceptional Conditions
Published
2026-04-09T21:35Z
EPSS history
Timeline
  • 09 APR 21:35Z
    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
    cvelistv5