Junos OS (SRX firewalls)
CVE-2026-102050: An adjacent attacker causes Layer 2 control-plane denial of service when LLDP is enabled
A Stack-based Buffer Overflow vulnerability in the l2cpd daemon of Juniper Networks Junos OS and Junos OS Evolved allows an unauthenticated adjacent attacker to cause a denial of service in Layer 2 control-plane processing via LLDP packets received on an interface configured for LLDP.
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
A stack-based buffer overflow in the l2cpd daemon allows an unauthenticated attacker on an adjacent network to send crafted LLDP packets to a configured interface. This action causes a denial of service in Layer 2 control-plane processing, which can disrupt LLDP and other Layer 2 control protocols across the device. No login or user interaction is required to exploit this flaw.
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 l2cpd daemon of Juniper Networks Junos OS and Junos OS Evolved allows an unauthenticated adjacent attacker to cause a denial of service in Layer 2 control-plane processing via LLDP packets received on an interface configured for LLDP. Repeated triggering may disrupt LLDP and other Layer 2 control protocols across the device.
Am I affected?
[ protocols lldp interface <interface> ]
Workarounds
Disable LLDP if it is not required.
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.