Vulnerability · Published Apr 9, 2026 · Assigned by juniper

CVE-2026-33797Junos OS and Junos OS Evolved: An attacker sending a specific genuine BGP packet causes a BGP reset

High 7.4

In plain English

A high-severity improper input validation in Junos OS from Juniper Networks. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.2% (higher than 7% of all known vulnerabilities).

Severity (CVSS 3.1)7.4High

Exploit odds (30 days)0.2%top 93.1% of all CVEs

Exploited in the wildNo reportsCISA SSVC: none

Attack toolingNoneno public tooling known

Official description

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 does not affect Junos OS versions before 25.2R1. This issue affects Junos OS Evolved: * 25.2-EVO versions before 25.2R2-EVO This issue does not affect Junos OS Evolved versions before 25.2R1-EVO. eBGP and iBGP are affected. IPv4 and IPv6 are affected.

Affected products (as reported)

Vendor	Product	Versions
Juniper Networks	Junos OS	25.2 – before 25.2R2
Juniper Networks	Junos OS Evolved	25.2 – before 25.2R2-EVO

Weakness: CWE-20 · Vector: CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H

References

https://kb.juniper.net/JSA107850 vendor-advisory
https://supportportal.juniper.net/JSA107850 vendor-advisory