Vulnerability in Juniper Junos

CVE-2025-30660

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.

Published · last modified .

CVSS v3 metric

CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.

EPSS exploit prediction

EPSS: 0.004 (36.7th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 37th percentile — 36.7% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2025-30660: held from 0.004 to 0.004.

EPSS over last 30 days · oldest: 0.004 · newest: 0.004 · change: +0.000

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2025-30660?
CVE-2025-30660 is a high-severity vulnerability in Juniper Junos, classified under Improper Check for Unusual or Exceptional Conditions. CVSS score: 7.5/10. Published 2025-04-09.
How severe is CVE-2025-30660?
High severity. CVSS v3 base score is 7.5 out of 10.