CVE-2026-33797
CWE-20Published: April 9, 2026· Updated: Apr 16, 2026
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 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.
Technical Analysis
CVE-2026-33797 requires adjacent network access, limiting remote exploitation but still posing risk in shared or local network environments.
The vulnerability requires no privileges and no user interaction, making it a prime target for automated exploitation campaigns and worm-like propagation.
A successful exploit results in availability disruption (denial of service), with a CVSS base score of 7.4.
The vulnerability has a "Changed" scope, meaning successful exploitation can impact components beyond the vulnerable component itself — such as the host operating system or adjacent services.
A proof-of-concept (PoC) exploit exists for CVE-2026-33797. While not yet confirmed in active campaigns, the availability of PoC code increases exploitation risk substantially.
CVSS v3.1 Vector Breakdown
Affected Vendors & Products
Exploit & PoC Resources
Official Patches & Advisories
All References (1)
Quick Facts
Related CVEs (CWE-20)
Recommended Actions
- →Apply vendor patches immediately
- →Monitor CVE-2026-33797 in threat intel feeds
- →Review IDS/IPS signatures for exploitation attempts