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 products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| Juniper Networks | Junos OS | < 22.4R3-S8, 23.2 – < 23.2R2-S5, 23.4 – < 23.4R2 | 22.4R3-S8 |
| Juniper Networks | Junos OS Evolved | < 22.4R3-S8-EVO, 23.2 – < 23.2R2-S5-EVO, 23.4 – < 23.4R2-EVO | 22.4R3-S8-EVO |
Advisories 2
- NCSC-2026-0017 Kwetsbaarheden verholpen in Juniper Networks JunOS NCSC-NL (Netherlands) · Jan 16, 2026
- WID-SEC-2026-0117 Juniper Junos OS, Junos Space: Mehrere Schwachstellen BSI CERT-Bund (WID) · Jan 15, 2026
References
- https://supportportal.juniper.net/JSA106021 vendor-advisory
- https://kb.juniper.net/JSA106021 vendor-advisory