🛡️ CVE-2026-21921
🟡 CVSS 6.5 — Medium ✅ No Known Exploit CWE-416 NVD
6.5
CVSS Score
0 Low4 Medium7 High9 Critical10

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.

Details

Severity MEDIUM
CVSS Score 6.5
CVSS Vector CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
CWE CWE-416
Public Exploit ✅ No
Source NVD
Published 2026-01-15
Updated 2026-06-02
Modified 2026-01-23
Fix URL N/A

Affected Packages

Software From version Fixed in
junos — —
junos-os-evolved — —

Similar Threats

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