CVE-2026-33801 Junos OS and Junos OS Evolved: When a specifically malformed BGP route update is received RPD crashes
An adjacent attacker can crash the routing daemon via a malformed BGP update, causing a service outage until routing reconverges.
- 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-2026-33801?
CVE-2026-33801 is a high-severity denial of service vulnerability in Juniper Junos, published on 9 Jul 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
An Improper Check for Unusual or Exceptional Conditions vulnerability in the routing protocol daemon (RPD) of Juniper Networks Junos OS and Junos OS Evolved allows an adjacent, unauthenticated attacker sending a specific BGP update over an established BGP session to cause a Denial-of-Service (DoS).
Upon receipt of a specifically malformed non-inet/inet6 unicast BGP update, an RPD crash and restart is triggered, which will cause a complete service outage until routing has reconverged. The rpd crash occurs before the update can be readvertised, so there is no downstream propagation.
This issue affects:
* Junos OS versions 25.2 before 25.2R2;
* Junos OS Evolved versions 25.2 before 25.2R2-EVO.
This issue doesn't affect Junos OS versions before 25.2R1 nor Junos OS Evolved versions before 25.2R1-EVO.
Weakness: CWE-754
Which versions are affected by CVE-2026-33801?
It affects 2 products.
Products include Juniper Junos, Juniper Junos Os Evolved.
How do I fix CVE-2026-33801?
No fix has been published for CVE-2026-33801 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-2026-33801 being exploited?
There is no known exploitation of CVE-2026-33801 in the wild and no public exploit code.
Other vulnerabilities in Juniper Junos
- CVE-2023-36845 Juniper Junos OS EX Series and SRX Series PHP External Variable Modification
- CVE-2020-1631 Juniper Junos OS Path Traversal
- CVE-2025-21590 Juniper Junos OS Improper Isolation or Compartmentalization
- CVE-2023-36851 Juniper Junos OS SRX Series Missing Authentication for Critical Function
- CVE-2023-36844 Juniper Junos OS EX Series PHP External Variable Modification
Sources
Also known as GHSA-cv9f-44gv-7rg6.