Juniper Junos OS: 2026-04 Security Bulletin: Junos OS and Junos OS Evolved: An attacker sending a specific genuine BGP packet causes a BGP reset (JSA107850) (CVE-2026-33797)

An Improper Input Validation vulnerability in Juniper Networks Junos OS and Junos OS Evolved allows an unauthenticated, adjacent attacker, sending a specific genuine BGP packet in an already established BGP session to reset only that session causing a Denial of Service (DoS).

An attacker repeatedly sending the packet will sustain the Denial of Service (DoS).This issue affects Junos OS:

* 25.2 versions before 25.2R2

This issue doesn't not affected Junos OS versions before 25.2R1.

This issue affects Junos OS Evolved:
* 25.2-EVO versions before 25.2R2-EVO

This issue doesn't not affected Junos OS Evolved versions before 25.2R1-EVO.

eBGP and iBGP are affected.
IPv4 and IPv6 are affected.