Vulnerability in Juniper Junos
CVE-2026-21909
A Missing Release of Memory after Effective Lifetime vulnerability in the routing protocol daemon (rpd) Juniper Networks Junos OS and Junos OS Evolved allows an unauthenticated attacker controlling an adjacent IS-IS neighbor to send a spec…
EPSS: 0.002 (14.4th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 6.5 (Medium). Vector: CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.
Affected products
- Juniper Junos — versions 23.2, 23.4, 24.1
- Juniper Junos_os_evolved — versions 23.2, 23.4, 24.1
- Juniper Networks Junos Os — versions 23.2, 23.4, 24.1
- Juniper Networks Junos Os Evolved — versions 23.2, 23.4, 24.1
Weakness classification (CWE)
References
- sirt@juniper.net (vendor-advisory, Vendor Advisory)
- sirt@juniper.net (vendor-advisory, Vendor Advisory)
Frequently asked questions
- What is CVE-2026-21909?
- CVE-2026-21909 is a medium-severity vulnerability in Juniper Junos, classified under Missing Release of Memory after Effective Lifetime. CVSS score: 6.5/10. Published 2026-01-15.
- How severe is CVE-2026-21909?
- Medium severity. CVSS v3 base score is 6.5 out of 10.