Improper input validation in Junos OS - CVE-2026-33778
Published: April 9, 2026
Vulnerability identifier: #VU125558
CSH Severity: Medium
CVSS v4.0: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Green
CVE-ID: CVE-2026-33778
CWE-ID: CWE-20
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vendor: Juniper Networks, Inc.
Affected software:
Junos OS
Junos OS
Detailed vulnerability description
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.
How to mitigate CVE-2026-33778
Install security update from vendor's website.