This vulnerability (CVE-2026-33794) in Juniper Networks Junos OS Evolved affects the advanced forwarding toolkit (evo-aftmand) on PTX Series devices. It arises from an improper check for unusual or exceptional conditions when processing unified list ECMP routing updates. An unauthenticated network-based attacker can send continuous routing updates that cause internal state corruption in the evo-aftmand process, leading to its crash and a denial-of-service condition on the Packet Forwarding Engine. The exploitation requires a sequence of events outside the attacker's direct control. Affected versions include 24.4R2-EVO prior to 24.4R2-S3-EVO and version 25.2 prior to 25.2R2-EVO. Juniper manages remediation for this cloud-hosted service, and a patch is available.

Successful exploitation results in a denial-of-service condition by crashing the evo-aftmand process on the PFE, causing the device to require manual intervention such as rebooting or restarting the FPC. There is no impact on confidentiality or integrity. The vulnerability requires network access but no privileges or user interaction. The CVSS v3.1 base score is 5.9 (medium severity).

A patch is available for this vulnerability. Juniper Networks manages remediation for this cloud-hosted service; users should consult the vendor advisory for patch deployment and confirmation of mitigation status. No additional action is required beyond applying the official fix or vendor-provided updates.