CVE-2026-102033 Junos OS and Junos OS Evolved: An attacker causes denial of service when MC-LAG MAC synchronization is enabled
An adjacent attacker can cause a denial of service in Juniper Junos OS via ICCP MC-LAG messages when MAC synchronization is enabled.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-102033?
CVE-2026-102033 is a high-severity denial of service vulnerability in Juniper Networks Junos OS, published on 14 Oct 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
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.
Weakness: CWE-1284
Which versions are affected by CVE-2026-102033?
How do I fix CVE-2026-102033?
No fix has been published for CVE-2026-102033 yet. Limit exposure of the affected software until one is available.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2026-102033 being exploited?
There is no known exploitation of CVE-2026-102033 in the wild and no public exploit code.
Sources
Also known as GHSA-jmcp-3737-hhw7.