CVE-2026-21918

7.5 HIGH
Published: January 15, 2026 Modified: January 23, 2026
View on NVD

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.

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CVSS v3.x Details

0.0 Low Medium High Critical 10.0
Vector String
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

References to Advisories, Solutions, and Tools

Patch Vendor Advisory Exploit Third Party Advisory
https://kb.juniper.net/JSA106018
Source: sirt@juniper.net
Vendor Advisory
https://supportportal.juniper.net/JSA106018
Source: sirt@juniper.net
Vendor Advisory

2 reference(s) from NVD

Quick Stats

CVSS v3 Score
7.5 / 10.0
EPSS (Exploit Probability)
0.0%
4th percentile
Exploitation Status
Not in CISA KEV

Weaknesses (CWE)

Affected Vendors

juniper