CVE-2026-102033: Junos OS and Junos OS Evolved: An attacker causes denial of service when MC-LAG MAC synchronization is enabled

Published Oct 14, 2026

Updated

An Improper Validation of Specified Quantity in Input vulnerability in l2ald of Juniper Networks Junos OS and Junos OS Evolved allows an adjacent attacker to cause a denial of service via an ICCP MC-LAG message.

Affected Software

2 affected components

Juniper Networks Junos OS

Juniper Networks Junos OS Evolved

Remediation

Recommended actions to resolve this vulnerability, in priority order.

Upgrade
Upgrade Juniper Junos OS Evolved to a version that resolves this vulnerability.
Fixed in 23.2R2-S7.7-EVO
Upgrade
Upgrade Juniper Junos OS Evolved to a version that resolves this vulnerability.
Fixed in 23.4R2-S8.11-EVO
Upgrade
Upgrade Juniper Junos OS Evolved to a version that resolves this vulnerability.
Fixed in 24.2R2-S5.6-EVO
Upgrade
Upgrade Juniper Junos OS Evolved to a version that resolves this vulnerability.
Fixed in 24.4R2-S5-EVO
Upgrade
Upgrade Juniper Junos OS Evolved to a version that resolves this vulnerability.
Fixed in 25.2R2-S2-EVO
Upgrade
Upgrade Juniper Junos OS Evolved to a version that resolves this vulnerability.
Fixed in 25.2X100-D35-EVO
Upgrade
Upgrade Juniper Junos OS Evolved to a version that resolves this vulnerability.
Fixed in 25.4R1-S3-EVO
Upgrade
Upgrade Juniper Junos OS Evolved to a version that resolves this vulnerability.
Fixed in 25.4R2-EVO
Upgrade
Upgrade Juniper Junos OS Evolved to a version that resolves this vulnerability.
Fixed in 25.4X300-D40-EVO
Upgrade
Upgrade Juniper Junos OS Evolved to a version that resolves this vulnerability.
Fixed in 26.2R1-S2-EVO
Upgrade
Upgrade Juniper Junos OS Evolved to a version that resolves this vulnerability.
Fixed in 26.2R2-EVO
Upgrade
Upgrade Juniper Junos OS Evolved to a version that resolves this vulnerability.
Fixed in 26.4R1-EVO
Upgrade
Upgrade Juniper Junos OS to a version that resolves this vulnerability.
Fixed in 23.2R2-S7.7
Upgrade
Upgrade Juniper Junos OS to a version that resolves this vulnerability.
Fixed in 23.4R2-S8.13
Upgrade
Upgrade Juniper Junos OS to a version that resolves this vulnerability.
Fixed in 24.2R2-S5.5
Upgrade
Upgrade Juniper Junos OS to a version that resolves this vulnerability.
Fixed in 24.4R2-S5
Upgrade
Upgrade Juniper Junos OS to a version that resolves this vulnerability.
Fixed in 25.2R2-S2
Upgrade
Upgrade Juniper Junos OS to a version that resolves this vulnerability.
Fixed in 25.4R1-S3
Upgrade
Upgrade Juniper Junos OS to a version that resolves this vulnerability.
Fixed in 25.4R2
Upgrade
Upgrade Juniper Junos OS to a version that resolves this vulnerability.
Fixed in 26.2R1-S2
Upgrade
Upgrade Juniper Junos OS to a version that resolves this vulnerability.
Fixed in 26.2R2
Upgrade
Upgrade Juniper Junos OS to a version that resolves this vulnerability.
Fixed in 26.4R1

Event History

Oct 14, 2026

CVE Published

via MITRE·04:50 PM

Data Sourced

via MITRE·04:50 PM

RemedyDescriptionSeverityWeakness

Frequently Asked Questions

Does exploitation require authentication or user interaction?

No. The vulnerability is rated with no privileges required and no user interaction required.

What network access does an attacker need?

The attacker must be adjacent to the affected device and able to send an ICCP MC-LAG message.

Is every Junos deployment affected?

Exposure depends on MC-LAG MAC synchronization being enabled. The affected software families are Junos OS and Junos OS Evolved.