Junos OS kmd/iked ISAKMP DoS; before 22.4R3 & 23.2R2
CVE-2026-33778 Published on April 9, 2026
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.
Vulnerability Analysis
CVE-2026-33778 is exploitable with network access, and does not require authorization privileges or user interaction. This vulnerability is considered to have a low attack complexity. The potential impact of an exploit of this vulnerability is considered to have no impact on confidentiality and integrity, and a high impact on availability.
Weakness Type
Improper Validation of Syntactic Correctness of Input
The product receives input that is expected to be well-formed - i.e., to comply with a certain syntax - but it does not validate or incorrectly validates that the input complies with the syntax.
Products Associated with CVE-2026-33778
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Affected Versions
Juniper Networks Junos OS:- Before 22.4R3-S9 is affected.
- Version 23.2 and below 23.2R2-S6 is affected.
- Version 23.4 and below 23.4R2-S7 is affected.
- Version 24.2 and below 24.2R2-S4 is affected.
- Version 24.4 and below 24.4R2-S3 is affected.
- Version 25.2 and below 25.2R1-S2, 25.2R2 is affected.
Exploit Probability
EPSS (Exploit Prediction Scoring System) scores estimate the probability that a vulnerability will be exploited in the wild within the next 30 days. The percentile shows you how this score compares to all other vulnerabilities.