What is CVE-2026-33797?

CVE-2026-33797 is a high-severity vulnerability in Juniper Junos, classified under Improper Input Validation. CVSS score: 7.4/10. Published 2026-04-09.

How severe is CVE-2026-33797?

High severity. CVSS v3 base score is 7.4 out of 10.

Improper input validation in Juniper Junos

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 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.

Vulnerability class: Drupalgeddon 2 (CVE-2018-7600)

EPSS: 0.002 (6.2th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 7.4 (High). Vector: CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H.

Affected products

Juniper Junos — versions 25.2
Juniper Junos_os_evolved — versions 25.2
Juniper Networks Junos Os — versions 25.2, 0
Juniper Networks Junos Os Evolved — versions 25.2, 0

Weakness classification (CWE)

CWE-20 — Improper Input Validation

References

sirt@juniper.net (vendor-advisory, Vendor Advisory)
sirt@juniper.net (vendor-advisory)

Frequently asked questions

What is CVE-2026-33797?: CVE-2026-33797 is a high-severity vulnerability in Juniper Junos, classified under Improper Input Validation. CVSS score: 7.4/10. Published 2026-04-09.
How severe is CVE-2026-33797?: High severity. CVSS v3 base score is 7.4 out of 10.