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National Vulnerability Database

National Vulnerability Database

NVD

National Vulnerability Database
  1. Vulnerabilities

CVE-2026-21912 Detail

Description

A Time-of-check Time-of-use (TOCTOU) Race Condition vulnerability in the method to collect FPC Ethernet firmware statistics of Juniper Networks Junos OS on MX10k Series allows a local, low-privileged attacker executing the 'show system firmware' CLI command to cause an LC480 or LC2101 line card to reset. On MX10k Series systems with LC480 or LC2101 line cards, repeated execution of the 'show system firmware' CLI command can cause the line card to crash and restart. Additionally, some time after the line card crashes, chassisd may also crash and restart, generating a core dump.This issue affects Junos OS on MX10k Series:  * all versions before 21.2R3-S10,  * from 21.4 before 21.4R3-S9,  * from 22.2 before 22.2R3-S7,  * from 22.4 before 22.4R3-S6,  * from 23.2 before 23.2R2-S2,  * from 23.4 before 23.4R2-S3,  * from 24.2 before 24.2R2.


Metrics

 
NVD enrichment efforts reference publicly available information to associate vector strings. CVSS information contributed by other sources is also displayed.
CVSS 4.0 Severity and Vector Strings:

NIST CVSS score
NIST: NVD
N/A
NVD assessment not yet provided.

Nist CVSS score does not match with CNA score
CNA:  Juniper Networks, Inc.
CVSS-B 6.8 MEDIUM
Vector:  CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:L/AU:Y/R:A/RE:M/U:Amber

References to Advisories, Solutions, and Tools

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URL Source(s) Tag(s)
https://kb.juniper.net/JSA106011 Juniper Networks, Inc.
https://supportportal.juniper.net/JSA106011 Juniper Networks, Inc.

Weakness Enumeration

CWE-ID CWE Name Source
CWE-367 Time-of-check Time-of-use (TOCTOU) Race Condition Juniper Networks, Inc.  

Change History

1 change records found show changes

Quick Info

CVE Dictionary Entry:
CVE-2026-21912
NVD Published Date:
01/15/2026
NVD Last Modified:
01/16/2026
Source:
Juniper Networks, Inc.