Junos OS (SRX firewalls)
CVE-2026-101996: An inconsistent ICCP peer message causes an l2ald crash when MC-LAG is configured
A Reachable Assertion vulnerability in the l2ald daemon of Juniper Networks Junos OS and Junos OS Evolved devices configured for MC-LAG/ICCP allows an adjacent attacker to cause a denial of service via an inconsistent ICCP peer message.
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 reachable assertion flaw in the l2ald daemon of Junos OS and Junos OS Evolved devices configured for MC-LAG/ICCP allows an attacker to trigger a denial of service. By sending an inconsistent ICCP peer message from an adjacent network, the attacker can crash the daemon without needing to log in or interact with any user.
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 Reachable Assertion vulnerability in the
l2ald
daemon of Juniper Networks Junos OS and Junos OS Evolved devices configured for MC-LAG/ICCP allows an adjacent attacker to cause a denial of service via an inconsistent ICCP peer message.
Am I affected?
[ protocols iccp peer ]
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.