SB2026012019 - Memory leak in Junos OS Evolved and Juniper Junos OS
Published: January 20, 2026
Security Bulletin ID
SB2026012019
Severity
Medium
Patch available
YES
Number of vulnerabilities
1
Exploitation vector
Adjecent network
Highest impact
Denial of service
Breakdown by Severity
- Low
- Medium
- High
- Critical
Description
This security bulletin contains information about 1 security vulnerability.
1) Memory leak (CVE-ID: CVE-2026-21909)
The vulnerability allows a remote non-authenticated attacker to perform a denial of service (DoS) attack.
The vulnerability exists due to missing release of memory after effective lifetime error in the routing protocol daemon (rpd). A remote non-authenticated attacker can send a specific update packet causing a memory leak.
Remediation
Install update from vendor's website.