CVE-2026-102080 Junos OS: MX Series: Malformed SyncE or PTP clock input causes continuous RE switchover
A race condition in the clock synchronization daemon allows an adjacent attacker to cause continuous router engine switchovers and denial of service.
- 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-2026-102080?
CVE-2026-102080 is a medium-severity 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 Resource Locking vulnerability in the clock synchronization daemon (clksyncd) of Juniper Networks Junos OS on MX Series allows a unauthenticated, logically adjacent attacker to cause a Denial-of-Service (DoS).
If a SyncE or PTP upstream node sends a malformed message to an MX device equipped with SCBE3, a false 19.44MHz alarm is generated on the master RE. This leads to persistent RE switchovers and a clksyncd process crash. This issue is outside the attacker's direct control as it's a race condition.
This issue affects Junos OS on MX Series:
* All versions before 23.2R2-S7.7; * 23.4 versions before 23.4R2-S8.13; * 24.2 versions before 24.2R2-S5.5; * 24.4 versions before 24.4R2-S4; * 25.2 versions before 25.2R2-S1; * 25.4 versions before 25.4R1-S2.
Weakness: CWE-413
Which versions are affected by CVE-2026-102080?
How do I fix CVE-2026-102080?
No fix has been published for CVE-2026-102080 yet. Limit exposure of the affected software until one is available.
Is CVE-2026-102080 being exploited?
There is no known exploitation of CVE-2026-102080 in the wild and no public exploit code.
Sources
Also known as GHSA-gvgv-h84m-5m5q.