Junos OS (SRX firewalls)
CVE-2025-59964: SRX4700: When forwarding-options sampling is enabled any traffic destined to the RE will cause the forwarding line card to crash and restart
A Use of Uninitialized Resource vulnerability in the Packet Forwarding Engine (PFE) of Juniper Networks Junos OS on SRX4700 devices allows an unauthenticated, network-based attacker to cause a Denial of Service (DoS).
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 (SRX4700) 24.4 | 24.4R1-S3, 24.4R2 or later |
Always confirm against the vendor advisory, which lists every fixed hotfix.
What it is
A Use of Uninitialized Resource vulnerability in the Packet Forwarding Engine (PFE) of Juniper Networks Junos OS on SRX4700 devices allows an unauthenticated, network-based attacker to cause a Denial of Service (DoS).
When forwarding-options sampling is enabled, receipt of any traffic destined to the Routing Engine (RE) by the PFE line card leads to an FPC crash and restart, resulting in a Denial of Service (DoS).
Continued receipt and processing of any traffic leading to the RE by the PFE line card will create a sustained Denial of Service (DoS) condition to the PFE line card.
This issue affects Junos OS on SRX4700:
- from 24.4 before 24.4R1-S3, 24.4R2
This issue affects IPv4 and IPv6.
Am I affected?
Below is the configuration to check if sampling is enabled.
[ forwarding-options sampling ]
Workarounds
To workaround this issue an administrator must block all traffic from the PFE line card to the Routing Engine (RE) until a fix can be taken. Even while under a persistent DoS attack the RE will continue to be accessible to administrators through non-PFE line card interfaces E.g. Console, FXP0.
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.