Improper Check for Unusual or Exceptional Conditions in Junos OS - CVE-2026-33781
Published: May 8, 2026
Vulnerability identifier: #VU130703
CSH Severity: Medium
CVSS v4: 7.1 [CVSS:4.0/AV:A/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-33781
CWE-ID: CWE-754
Exploitation vector: Adjecent network
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote attacker to cause a denial of service.
The vulnerability exists due to improper check for unusual or exceptional conditions in the packet forwarding engine (pfe) when receiving VSTP BPDUs on UNI interfaces in VXLAN scenarios. A remote attacker can send specific control protocol packets to cause a denial of service.
Exploitation requires EX4k or QFX5k platforms configured as service-provider edge devices with L2PT enabled on the UNI and VSTP enabled on NNI.
Affected software
Junos OS
How to mitigate CVE-2026-33781
Install security update from vendor's website.
Junos OS - addressed in versions 24.4R2, 25.2R1-S1, 25.2R2, 25.4R1