CVE-2025-59958: Juniper Junos OS Evolved

Medium severity, CVSS 6.5. EPSS: 0.3% chance of exploitation in the next 30 days.

An Improper Check for Unusual or Exceptional Conditions vulnerability in the Packet Forwarding Engine (PFE) of Juniper Networks Junos OS Evolved on PTX Series allows an unauthenticated, network-based attacker to cause impact to confidentiality and availability. When an output firewall filter is configured with one or more terms where the action is 'reject', packets matching these terms are erroneously sent to the Routing Engine (RE) and further processed there. Processing of these packets will consume limited RE resources. Also responses from the RE back to the source of this traffic could reveal confidential information about the affected device. This issue only applies to firewall filters applied to WAN or revenue interfaces, so not the mgmt or lo0 interface of the routing-engine, nor any input filters. This issue affects Junos OS Evolved on PTX Series: * all versions before 22.4R3-EVO, * 23.2 versions before 23.2R2-EVO.

Affected products

• Juniper Junos OS Evolved: before 22.4 (fixed in 22.4); version 22.4 only; version 23.2 only

Published 2025-10-09. Last modified 2026-10-08.