SB2026040942 - Remote denial of service in Junos OS IPsec



SB2026040942 - Remote denial of service in Junos OS IPsec

Published: April 9, 2026

Security Bulletin ID SB2026040942
Severity
Medium
Patch available
YES
Number of vulnerabilities 1
Exploitation vector Remote access
Highest impact Denial of service

Breakdown by Severity

Medium 100%
  • Low
  • Medium
  • High
  • Critical

Description

This security bulletin contains information about 1 security vulnerability.


1) Improper input validation (CVE-ID: CVE-2026-33778)

The vulnerability allows a remote attacker to cause a denial of service.

The vulnerability exists due to improper validation of syntactic correctness of input in the IPsec library used by kmd and iked when processing a specifically malformed first ISAKMP packet. A remote attacker can send a specifically malformed first ISAKMP packet to cause a denial of service.

Successful exploitation crashes and restarts the kmd/iked process, which momentarily prevents new security associations from being established. Repeated exploitation can prevent new VPN connections from being established.


Remediation

Install update from vendor's website.