Junos OS (SRX firewalls)
CVE-2026-102056: An attacker causes denial of service and information disclosure when Ethernet CFM is enabled
An Out-of-bounds Read vulnerability in the cfmd process of Juniper Networks Junos OS and Junos OS Evolved allows an unauthenticated adjacent-network attacker to crash the daemon and disclose limited process memory via a specific CFM Message sent to a configured interface.
Published Juniper Networks advisory JSA112187
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
An out-of-bounds read flaw in the cfmd process of Junos OS allows an unauthenticated attacker on an adjacent network to crash the daemon and disclose limited process memory. The attacker achieves this by sending a specific CFM message to a configured interface, requiring no login or user interaction.
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
An Out-of-bounds Read vulnerability in the cfmd process of Juniper Networks Junos OS and Junos OS Evolved allows an unauthenticated adjacent-network attacker to crash the daemon and disclose limited process memory via a specific CFM Message sent to a configured interface.
Am I affected?
Sample configuration for MEP:
[ protocols oam ethernet connectivity-fault-management maintenance-domain md4 level 4 ] [ protocols oam ethernet connectivity-fault-management maintenance-domain md4 maintenance-association ma4 continuity-check interval 1s ] [ protocols oam ethernet connectivity-fault-management maintenance-domain md4 maintenance-association ma4 continuity-check hold-interval 1 ] [ protocols oam ethernet connectivity-fault-management maintenance-domain md4 maintenance-association ma4 mep <id> interface <interface> ] [ protocols oam ethernet connectivity-fault-management maintenance-domain md4 maintenance-association ma4 mep <id> direction down ] [ protocols oam ethernet connectivity-fault-management maintenance-domain md4 maintenance-association ma4 mep <id> auto-discovery ]
OR
Sample configuration for MIP:
[ protocols oam ethernet connectivity-fault-management maintenance-domain default-4 mip-half-function default ]
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.