CVEvulnerability
CVE-2026-21921
7.1 HIGH
Official page ↗
- Status
- Analyzed
- Published
- 2026-01-15
- Last modified
- 2026-06-17
- Assigner
- [email protected]
- CVSS 4.0 ([email protected])
- 7.1 HIGH — 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
- CVSS 3.1 ([email protected])
- 6.5 MEDIUM — CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
- Weaknesses
- CWE-416
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.
Affected configurations
• juniper junos (< 22.4)
• juniper junos 22.4
• juniper junos 23.2
• juniper junos 23.4
• juniper junos os evolved (< 22.4)
• juniper junos os evolved 22.4
• juniper junos os evolved 23.2
• juniper junos os evolved 23.4
Related
Weakness · CWE (1)
- CWE-416 Use After Free weakness
References
- https://kb.juniper.net/JSA106021 Vendor Advisory
- https://supportportal.juniper.net/JSA106021 Vendor Advisory