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)
Published · last modified .
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.
EPSS exploit prediction
EPSS: 0.003 (17.2th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 17th percentile — 17.2% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.002 · newest: 0.003 · change: +0.001
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)
References
- kb.juniper.net/JSA107850 (vendor-advisory, Vendor Advisory)
- supportportal.juniper.net/JSA107850 (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.