EUVD-2026-21197
GHSA-q559-6pc6-gxfh
CVSS Vector
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:L/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:Y/R:X/V:X/RE:M/U:X
Lifecycle Timeline
3Tags
Description
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.
Analysis
Remote denial-of-service in Juniper Networks Junos OS (SRX/MX Series) allows unauthenticated attackers to crash IPsec daemons via malformed ISAKMP packets. Exploiting the improper input validation (CWE-1286) in kmd/iked IPsec library causes process restart, preventing new VPN security association establishment. …
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Remediation
Within 24 hours: Inventory all Juniper SRX and MX Series devices in production and document current Junos OS versions; contact Juniper Networks support for patch availability timeline and interim guidance. Within 7 days: Implement network segmentation to restrict ISAKMP traffic (UDP 500) to trusted source IPs only; enable syslog monitoring for iked/kmd daemon crashes with automated alerting. …
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