This vulnerability (CVE-2026-33794) in Juniper Networks Junos OS Evolved on PTX Series devices is due to an improper check for unusual or exceptional conditions in the evo-aftmand process, part of the advanced forwarding toolkit. An unauthenticated network-based attacker can trigger continuous routing updates that create unilist ECMP routes, which the system improperly processes. This can corrupt internal state and cause the evo-aftmand process on the PFE to crash, resulting in a denial-of-service. Recovery requires manual intervention such as rebooting the system or restarting the FPC. The affected versions are 24.4R2-EVO up to but not including 24.4R2-S3-EVO, and 25.2 up to but not including 25.2R2-EVO. The vendor provides patches, and as this is a cloud service, Juniper manages remediation for cloud deployments.

Successful exploitation causes the evo-aftmand process on the Packet Forwarding Engine to crash, resulting in a denial-of-service condition on affected Junos OS Evolved PTX devices. This disrupts normal routing operations and requires manual recovery actions such as rebooting or restarting the FPC. There is no impact on confidentiality or integrity, only availability is affected.

A patch is available from Juniper Networks for this vulnerability. Since Junos OS Evolved is a cloud service, Juniper manages remediation for cloud-hosted deployments. Users should apply the official patches 24.4R2-S3-EVO or later and 25.2R2-EVO or later to affected versions. Manual intervention is required to recover from a crash if exploitation occurs before patching.