Junos OS (SRX firewalls)
CVE-2026-101994: Malformed MC-LAG ICCP message causes l2ald heap disclosure or crash
An Improper Handling of Length Parameter Inconsistency vulnerability in the l2ald daemon of Juniper Networks Junos OS and Junos OS Evolved allows an attacker who can control or impersonate a configured MC-LAG ICCP peer to disclose process heap memory or cause a denial of service via a malformed ICCP 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 flaw in the l2ald daemon of Junos OS allows an attacker on an adjacent network to send a malformed ICCP message to a configured MC-LAG peer. This action can disclose process heap memory or cause a denial of service. The attack requires no authentication 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 Improper Handling of Length Parameter Inconsistency vulnerability in the
l2ald
daemon of Juniper Networks Junos OS and Junos OS Evolved allows an attacker who can control or impersonate a configured MC-LAG ICCP peer to disclose process heap memory or cause a denial of service via a malformed ICCP 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.