HomeJuniperCVE-2026-21920

CVE-2026-21920

HIGH
8.7CVSS
Published: 2026-01-15
Updated: 2026-01-15
AI Analysis

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 Metrics

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:A/V:X/RE:M/U:X
Attack Vector
network
Complexity
low
Privileges
none
User Action
none
Confidentiality
undefined
Integrity
undefined
Availability
undefined
Weaknesses
CWE-252

Metadata

Primary Vendor
JUNIPER
Published
1/15/2026
Last Modified
1/15/2026
Source
NIST NVD
Note: Verify all details with official vendor sources before applying patches.

Affected Products

Juniper : Refer to Description

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