Junos OS (SRX firewalls)
CVE-2025-30649: MX240, MX480, MX960 with SPC3: An attacker sending specific packets will cause a CPU utilization DoS.
An Improper Input Validation vulnerability in the syslog stream TCP transport of Juniper Networks Junos OS on MX240, MX480 and MX960 devices with MX-SPC3 Security Services Card allows an unauthenticated, network-based attacker, to send specific spoofed packets to cause a CPU Denial of Service (DoS) to the MX-SPC3 SPUs.
Published
Automatic summary from the vendor's CVE record. We haven't written a full analysis of this vulnerability yet.
Affected and fixed versions
| Product / branch | Fixed in |
|---|---|
| Junos OS (MX240, MX480, MX960, with SPC3) 0 | 22.2R3-S6 or later |
| Junos OS (MX240, MX480, MX960, with SPC3) 22.4 | 22.4R3-S4 or later |
| Junos OS (MX240, MX480, MX960, with SPC3) 23.2 | 23.2R2-S3 or later |
| Junos OS (MX240, MX480, MX960, with SPC3) 23.4 | 23.4R2-S4 or later |
| Junos OS (MX240, MX480, MX960, with SPC3) 24.2 | 24.2R1-S2, 24.2R2 or later |
Always confirm against the vendor advisory, which lists every fixed hotfix.
What it is
An Improper Input Validation vulnerability in the syslog stream TCP transport of Juniper Networks Junos OS on MX240, MX480 and MX960 devices with MX-SPC3 Security Services Card allows an unauthenticated, network-based attacker, to send specific spoofed packets to cause a CPU Denial of Service (DoS) to the MX-SPC3 SPUs.
Continued receipt and processing of these specific packets will sustain the DoS condition.
This issue affects Junos OS: * All versions before 22.2R3-S6, * from 22.4 before 22.4R3-S4, * from 23.2 before 23.2R2-S3, * from 23.4 before 23.4R2-S4, * from 24.2 before 24.2R1-S2, 24.2R2
An indicator of compromise will indicate the SPC3 SPUs utilization has spiked.
For example: user@device> show services service-sets summary Service sets CPU Interface configured Bytes used Session bytes used Policy bytes used utilization "interface" 1 "bytes" (percent%) "sessions" ("percent"%) "bytes" ("percent"%) 99.97 % OVLD <<<<<< look for high CPU usage
Am I affected?
[services service-set "service-set-name" syslog stream "stream-name" host "syslog-server-ip-address-or-hostname"] [services service-set "service-set-name" syslog stream "stream-name" host port "syslog-server-port"] [services service-set "service-set-name" syslog stream "stream-name" transport protocol tcp] [services service-set "service-set-name" syslog stream "stream-name" source-address "syslog-collector-ip-address"]
Workarounds
There are no known workarounds for this issue.
Exploitation
Juniper SIRT is not aware of any malicious exploitation of this vulnerability.
Sources
KEV status, EPSS score and vendor data refreshed automatically, last on 13 Oct 2026.