Junos OS (SRX firewalls)
CVE-2026-33798: SRX Series: An attacker causes remote code execution when SRX chassis-cluster is enabled
A Stack-based Buffer Overflow vulnerability in the srxpfe of Juniper Networks Junos OS and Junos OS Evolved on the SRX Series allows an L2-adjacent attacker to execute arbitrary code as root via high-availability fabric traffic.
Published Juniper Networks advisory JSA112186
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 0 | 23.2R2-S7.7 or later |
| Junos OS 23.4 | 23.4R2-S8.13 or later |
| Junos OS 24.2 | 24.2R2-S5.5 or later |
| Junos OS 24.4 | 24.4R2-S5 or later |
| Junos OS 25.2 | 25.2R2-S2 or later |
| Junos OS 25.4 | 25.4R1-S3 or later |
| Junos OS 26.2 | 26.2R1-S2 or later |
| Junos OS Evolved 0 | 23.2R2-S7.7-EVO or later |
| Junos OS Evolved 23.4 | 23.4R2-S8.11-EVO or later |
| Junos OS Evolved 24.2 | 24.2R2-S5.6-EVO or later |
| Junos OS Evolved 24.4 | 24.4R2-S5-EVO or later |
| Junos OS Evolved 25.2 | 25.2R2-S2-EVO or later |
| Junos OS Evolved 25.4 | 25.4R1-S3-EVO or later |
| Junos OS Evolved 26.2 | 26.2R1-S2-EVO or later |
| Junos OS Evolved 23.4X100 | See the advisory |
| Junos OS Evolved 25.2X100 | 25.2X100-D35-EVO or later |
| Junos OS Evolved 25.4X300 | 25.4X300-D40-EVO or later |
Always confirm against the vendor advisory, which lists every fixed hotfix.
In short
A stack-based buffer overflow in the srxpfe component of Junos OS on SRX Series firewalls allows an attacker to execute arbitrary code with root privileges. The attacker must be on an adjacent Layer 2 network and does not require authentication or user interaction. Exploitation is achieved by sending crafted high-availability fabric traffic to the device.
Written by a language model from the vendor's description. Versions, fixes and exploitation status on this page come straight from the vendor and CISA.
The vendor's description
A Stack-based Buffer Overflow vulnerability in the srxpfe of Juniper Networks Junos OS and Junos OS Evolved on the SRX Series allows an L2-adjacent attacker to execute arbitrary code as root via high-availability fabric traffic.
Am I affected?
This issue requires chassis-cluster to be configured. For example:
[ interfaces fab0 fabric-options member-interfaces <interface 1> ] [ interfaces fab1 fabric-options member-interfaces <interface 2> ]
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 19 Oct 2026.