CVE-2026-21920

Public PoC / Exploit

No public PoC or exploit code indexed for this CVE.

Links to public security research (Exploit-DB, Nuclei, Trickest, GitHub) for defensive use only.

Description

An Unchecked Return Value vulnerability in the DNS module of Juniper Networks Junos OS on SRX Series allows an unauthenticated, network-based attacker to cause a Denial-of-Service (DoS). If an SRX Series device configured for DNS processing, receives a specifically formatted DNS request flowd will crash and restart, which causes a service interruption until the process has recovered. This issue affects Junos OS on SRX Series: * 23.4 versions before 23.4R2-S5, * 24.2 versions before 24.2R2-S1, * 24.4 versions before 24.4R2. This issue does not affect Junos OS versions before 23.4R1.

CVSS Vector

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

Weaknesses (CWE)

CWE-252

Affected Products (35)

juniper · junosvulnerable

juniper · srx1500

juniper · srx1600

juniper · srx2300

juniper · srx300

juniper · srx320

juniper · srx340

juniper · srx345

juniper · srx380

juniper · srx4100

juniper · srx4120

juniper · srx4200

juniper · srx4300

juniper · srx4600

juniper · srx4700

juniper · srx5400

juniper · srx5600

juniper · srx5800

References (2)

https://kb.juniper.net/JSA106020

Vendor Advisory

https://supportportal.juniper.net/JSA106020

Vendor Advisory