CVE 7.5 HIGH

Junos OS: SRX and MX Series: When TCP packets occur in a specific sequence flowd crashes_CVE-2026-21918

7.5 / 10
HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Description

A Double Free vulnerability in the flow processing daemon (flowd) of Juniper Networks Junos OS on SRX and MX Series allows an unauthenticated, network-based attacker to cause a Denial-of-Service (DoS). On all SRX and MX Series platforms, when during TCP session establishment a specific sequence of packets is encountered a double free happens. This causes flowd to crash and the respective FPC to restart.





This issue affects Junos OS on SRX and MX Series:



* all versions before 22.4R3-S7,
* 23.2 versions before 23.2R2-S3,
* 23.4 versions before 23.4R2-S4,
* 24.2 versions before 24.2R2.

Basic Information

ID CVE-2026-21918
Source juniper
Published Jan 15, 2026 at 20:27

Affected Product

Vendor Juniper Networks
Product Junos OS
Affected Versions Juniper Networks Junos OS 0
Juniper Networks Junos OS 23.2
Juniper Networks Junos OS 23.4
Juniper Networks Junos OS 24.2

CWE Classification

References

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