CVE-2026-21909

6.5 MEDIUM
Published: January 15, 2026 Modified: January 23, 2026
View on NVD

Description

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 specific update packet causing a memory leak. Continued receipt and processing of these packets will exhaust all available memory, crashing rpd and creating a Denial of Service (DoS) condition. Memory usage can be monitored through the use of the 'show task memory detail' command. For example: user@junos> show task memory detail | match ted-infra   TED-INFRA-COOKIE           25   1072     28   1184     229 user@junos> show task memory detail | match ted-infra   TED-INFRA-COOKIE           31   1360     34   1472     307 This issue affects: Junos OS:  * from 23.2 before 23.2R2,  * from 23.4 before 23.4R1-S2, 23.4R2,  * from 24.1 before 24.1R2;  Junos OS Evolved:  * from 23.2 before 23.2R2-EVO,  * from 23.4 before 23.4R1-S2-EVO, 23.4R2-EVO,  * from 24.1 before 24.1R2-EVO. This issue does not affect Junos OS versions before 23.2R1 or Junos OS Evolved versions before 23.2R1-EVO.

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CVSS v3.x Details

0.0 Low Medium High Critical 10.0
Vector String
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

References to Advisories, Solutions, and Tools

Patch Vendor Advisory Exploit Third Party Advisory
https://kb.juniper.net/JSA106008
Source: sirt@juniper.net
Vendor Advisory
https://supportportal.juniper.net/JSA106008
Source: sirt@juniper.net
Vendor Advisory

2 reference(s) from NVD

Quick Stats

CVSS v3 Score
6.5 / 10.0
EPSS (Exploit Probability)
0.0%
1th percentile
Exploitation Status
Not in CISA KEV

Weaknesses (CWE)

Affected Vendors

juniper