Improper input validation in Junos OS - CVE-2026-33778
Published: April 9, 2026
Vulnerability identifier: #VU125558
CSH Severity: Medium
CVSS v4: 8.7 [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]
CVE-ID: CVE-2026-33778
CWE-ID: CWE-20
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
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.
Affected software
Junos OS
How to mitigate CVE-2026-33778
Install security update from vendor's website.
Junos OS - addressed in versions 22.4R3-S9, 23.2R2-S6, 23.4R2-S7, 24.2R2-S4, 24.4R2-S3, 25.2R1-S2, 25.2R2, 25.4R1