Unchecked Input for Loop Condition in Junos OS - CVE-2026-33800
Published: July 8, 2026
Vulnerability identifier: #VU137144
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-2026-33800
CWE-ID: CWE-606
Exploitation vector: Adjecent network
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote non-authenticated attacker to perform a denial of service (DoS) attack.
The vulnerability exists due to unchecked input for loop condition error in the Packet Forwarding Engine (pfe). A remote non-authenticated attacker can cause a Denial-of-Service (DoS).
Micro-BFD session flaps generate respective up/down events which are queued by PFEMAN for processing.
Especially in a Virtual-Chassis (VC) scenario with localitybias configured, processing takes a significant amount of time for each event.
Affected software
Junos OS
How to mitigate CVE-2026-33800
Install updates from vendor's website.
Junos OS - addressed in versions 23.2R2-S7, 23.4R2-S8, 24.2R2-S4, 24.4R2-S3, 25.2R2, 25.4R1