CVEvulnerability

CVE-2026-21901

6.7 MEDIUM Published 2026-07-09 Modified 2026-08-26 Official page ↗
Status
Analyzed
Published
2026-07-09
Last modified
2026-08-26
Assigner
[email protected]
CVSS 4.0 ([email protected])
6.7 MEDIUM — CVSS:4.0/AV:L/AC:L/AT:N/PR:H/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/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:D/RE:M/U:Green
CVSS 3.1 ([email protected])
4.4 MEDIUM — CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H
Weaknesses
CWE-476

Description

A NULL Pointer Dereference vulnerability in the management daemon (mgd) of Juniper Networks Junos OS and Junos OS Evolved allows a local, high-privileged attacker setting or deactivating a specific SSH configuration parameter to create a Denial of Service (DoS). A local high-privileged user configuring or deactivating a specific 'system services ssh' configuration parameter can exploit a null pointer dereference in one of the functions used by SSH. The function attempts to dereference a null pointer when accessing certain configuration data, resulting in an mgd process crash and restart. Continued execution of these configuration commands will create a sustained Denial of Service (DoS) condition. This issue affects: Junos OS: * from 22.3 before 22.3R3-S5; * from 22.4 before 22.4R3-S10; * from 23.2 before 23.2R2-S7; * from 23.4 before 23.4R2-S8. This issue does not affect Junos OS before 22.3R1. Junos OS Evolved: * from 22.3R1-EVO before 23.2R2-S7-EVO; * from 23.4 before 23.4R2-S8-EVO. This issue does not affect Junos OS Evolved before 22.3R1-EVO.

Affected configurations

• juniper junos 22.3 • juniper junos 22.4 • juniper junos 23.2 • juniper junos 23.4 • juniper junos os evolved 22.3 • juniper junos os evolved 22.4 • juniper junos os evolved 23.1 • juniper junos os evolved 23.2 • juniper junos os evolved 23.4

Related

Weakness · CWE (1)

  • CWE-476 NULL Pointer Dereference weakness

References