CVE-2026-33797: An Improper Input Validation vulnerability in Juniper Networks Junos OS and Junos OS Evolved allows an…

CVE-2026-33797 · Severity: high · CVSS 7.4 · Published 2026-04-09

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.

Technologies: Juniper Junos, Juniper Junos Os Evolved. Vendors: Juniper.

Quick answers

Is CVE-2026-33797 exploited in the wild?
No. Junglewise Threat Intelligence has no report of CVE-2026-33797 being exploited in the wild.
How severe is CVE-2026-33797?
High severity, with a CVSS score of 7.4, published 9 April 2026.
Which products and versions are affected?
Juniper Junos, Juniper Junos Os Evolved. The advisory does not name versions.
Is there a fix for CVE-2026-33797?
No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.
Am I affected by CVE-2026-33797?
Check whether you run Juniper Junos or Juniper Junos Os Evolved. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

Affected products

  • Juniper Junos
  • Juniper Junos Os Evolved

This page as Markdown. Free to reuse under CC BY 4.0 with a link back.