CVE-2025-30660: Juniper Junos

High severity, CVSS 7.5. EPSS: 0.4% 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 on MX Series allows an unauthenticated, network-based attacker to cause a Denial-of-Service (DoS).When processing a high rate of specific GRE traffic destined to the device, the respective PFE will hang causing traffic forwarding to stop. When this issue occurs the following logs can be observed: <fpc #> MQSS(0): LI-3: Received a parcel with more than 512B accompanying data CHASSISD_FPC_ASIC_ERROR: ASIC Error detected <...> This issue affects Junos OS: * all versions before 21.2R3-S9, * 21.4 versions before 21.4R3-S8, * 22.2 versions before 22.2R3-S4, * 22.4 versions before 22.4R3-S5, * 23.2 versions before 23.2R2-S2, * 23.4 versions before 23.4R2.

Affected products

• Juniper Junos: before 21.2 (fixed in 21.2); version 21.2 only; version 21.4 only; version 22.2 only; version 22.4 only; version 23.2 only; …

Published 2025-04-09. Last modified 2026-06-17.