Vulnerability ID: CVE-2026-21921 Affected Products: - Junos OS: All versions up to 22.4R3-S8, and specific versions in 23.2, 23.3, and 23.4 - Junos OS Evolved: All versions up to 22.4R3-S8-EVO, and specific versions in 23.2, 23.3, and 23.4 Severity: Medium CVSS Scores: - v3.1: 6.5 - v4.0: 7.1 Issue Description: A Use After Free vulnerability in the chassis daemon (chassisd) can cause telemetry-capable processes to crash and restart under certain conditions, potentially leading to a Denial of Service (DoS). Exploitation Conditions: Only occurs if GRPC services are configured on the device. Mitigation and Fix: - Updates are available in specific release versions for both Junos OS and Junos OS Evolved. - No known workarounds exist for this vulnerability.