CVE-2026-21921

HIGH EPSS 25.3%
Published Jan 15, 20265mo ago · Modified Jun 17, 20261w ago
7.1 CVSS 4.0
High
Find Similar
Published Jan 15, 2026 5mo ago
Last Modified Jun 17, 2026 1w ago

Description

A Use After Free vulnerability in the chassis daemon (chassisd) of Juniper Networks Junos OS and Junos OS Evolved allows a network-based attacker authenticated with low privileges to cause a Denial-of-Service (DoS). When telemetry collectors are frequently subscribing and unsubscribing to sensors continuously over a long period of time, telemetry-capable processes like chassisd, rpd or mib2d will crash and restart, which - depending on the process - can cause a complete outage until the system has recovered. This issue affects:  Junos OS:  * all versions before 22.4R3-S8, * 23.2 versions before 23.2R2-S5, * 23.4 versions before 23.4R2; Junos OS Evolved: * all versions before 22.4R3-S8-EVO, * 23.2 versions before 23.2R2-S5-EVO, * 23.4 versions before 23.4R2-EVO.

CVSS Details

Base Score
7.1
Exploitability
Impact
Vector string
CVSS:4.0/AV:N/AC:L/AT:N/PR:L/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
Attack Complexity Low
Privileges Required Low
User Interaction None
Scope X

Threat Intelligence

EPSS Exploit Probability
25.3% percentile
Exploit & Patch Status
No Known Exploit
No Patch Available

Weaknesses 1

CWE-416 Use After Free Memory Safety

Affected Products 58

VendorProductVersionRange
juniperjunos* <22.4
juniperjunos22.4any
juniperjunos22.4any
juniperjunos22.4any
juniperjunos22.4any
juniperjunos22.4any
juniperjunos22.4any
juniperjunos22.4any
juniperjunos22.4any
juniperjunos22.4any
juniperjunos22.4any
juniperjunos22.4any
juniperjunos22.4any
juniperjunos22.4any
juniperjunos22.4any
juniperjunos22.4any
juniperjunos23.2any
juniperjunos23.2any
juniperjunos23.2any
juniperjunos23.2any
juniperjunos23.2any
juniperjunos23.2any
juniperjunos23.2any
juniperjunos23.2any
juniperjunos23.2any
juniperjunos23.4any
juniperjunos23.4any
juniperjunos23.4any
juniperjunos23.4any
juniperjunos_os_evolved* <22.4
juniperjunos_os_evolved22.4any
juniperjunos_os_evolved22.4any
juniperjunos_os_evolved22.4any
juniperjunos_os_evolved22.4any
juniperjunos_os_evolved22.4any
juniperjunos_os_evolved22.4any
juniperjunos_os_evolved22.4any
juniperjunos_os_evolved22.4any
juniperjunos_os_evolved22.4any
juniperjunos_os_evolved22.4any
juniperjunos_os_evolved22.4any
juniperjunos_os_evolved22.4any
juniperjunos_os_evolved22.4any
juniperjunos_os_evolved22.4any
juniperjunos_os_evolved22.4any
juniperjunos_os_evolved23.2any
juniperjunos_os_evolved23.2any
juniperjunos_os_evolved23.2any
juniperjunos_os_evolved23.2any
juniperjunos_os_evolved23.2any
juniperjunos_os_evolved23.2any
juniperjunos_os_evolved23.2any
juniperjunos_os_evolved23.2any
juniperjunos_os_evolved23.2any
juniperjunos_os_evolved23.4any
juniperjunos_os_evolved23.4any
juniperjunos_os_evolved23.4any
juniperjunos_os_evolved23.4any

References 2

Remediation

No remediation data recorded yet

Check vendor advisories and the NVD entry for patch availability.