CVE-2026-102177 Junos OS and Junos OS Evolved: An out-of-bounds write causes an rpd crash when IS-IS backup selection is used
An adjacent attacker can crash the routing daemon via out-of-bounds write when IS-IS backup selection is configured.
- 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-2026-102177?
CVE-2026-102177 is a high-severity memory corruption 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 Out-of-bounds Write vulnerability in the routing protocol daemon (rpd) of Juniper Networks Junos OS and Junos OS Evolved allows an adjacent unauthenticated attacker to cause a denial of service when IS-IS link protection and backup-selection are configured.
Weakness: CWE-787
Which versions are affected by CVE-2026-102177?
How do I fix CVE-2026-102177?
No fix has been published for CVE-2026-102177 yet. Limit exposure of the affected software until one is available.
Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.
Is CVE-2026-102177 being exploited?
There is no known exploitation of CVE-2026-102177 in the wild and no public exploit code.
Sources
Also known as GHSA-88qg-2hgf-cg2r.