Home

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.

PUBLISHED Reserved 2026-03-23 | Published 2026-04-09 | Updated 2026-04-10 | Assigner juniper




MEDIUM: 6.5CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

HIGH: 7.1CVSS: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

Problem types

CWE-754 Improper Check for Unusual or Exceptional Conditions

Product status

Default status
unaffected

24.4 (semver) before 24.4R2
affected

25.2 (semver) before 25.2R1-S1, 25.2R2
affected

Any version before 24.4R1
unaffected

References

kb.juniper.net/JSA107869 vendor-advisory

cve.org (CVE-2026-33781)

nvd.nist.gov (CVE-2026-33781)

Download JSON