CVE-2026-33778: Junos OS: SRX Series, MX Series: When a specifically malformed first ISAKMP packet is received kmd/iked crashes
An Improper Validation of Syntactic Correctness of Input vulnerability in the IPsec library used by kmd and iked of Juniper Networks Junos OS on SRX Series and MX Series allows an unauthenticated, network-based attacker to cause a complete Denial-of-Service (DoS).
If an affected device receives a specifically malformed first ISAKMP packet from the initiator, the kmd/iked process will crash and restart, which momentarily prevents new security associations (SAs) for from being established. Repeated exploitation of this vulnerability causes a complete inability to establish new VPN connections.
This issue affects Junos OS on
SRX Series and MX Series:
all versions before 22.4R3-S9, 23.2 version before 23.2R2-S6, 23.4 version before 23.4R2-S7, 24.2 versions before 24.2R2-S4, 24.4 versions before 24.4R2-S3, 25.2 versions before 25.2R1-S2, 25.2R2.
Affected Software
Remediation
Information
Event History
Frequently Asked Questions
What is the severity of CVE-2026-33778?
CVE-2026-33778 is considered a medium severity vulnerability due to the potential for denial of service caused by the crashing of the kmd/iked process.
How do I fix CVE-2026-33778?
To fix CVE-2026-33778, you should upgrade to the latest version of Junos OS recommended by Juniper Networks.
Which products are affected by CVE-2026-33778?
CVE-2026-33778 affects Juniper Networks' Junos OS on SRX Series and MX Series devices.
What causes CVE-2026-33778?
CVE-2026-33778 is caused by an improper validation of the syntax of input in the IPsec library used by kmd and iked.
Can CVE-2026-33778 lead to unauthorized access?
CVE-2026-33778 does not directly lead to unauthorized access but can result in service disruption, impacting network security.