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Medium 5.5Published Jan 15, 2026

CVE-2026-21912Junos OS: MX10k Series: 'show system firmware' CLI command may lead to LC480 or LC2101 line card reset

Updated under an hour ago ()

Does this affect you?

It affects Juniper Networks Junos OS and 1 other product. Add what you run to find out whether that includes you.

No exploitation reported and no EPSS estimate yet.

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.

CVSS
5.5 MEDIUM (v3.1, CNA)CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Weakness (CWE)
CWE-367
Known exploited
Not in CISA's KEV catalog
EPSS (exploitation in the next 30 days)
Not loaded for this CVE
Assigned by
juniper
NVD analysis
Analyzed
Record last updated
Jan 15, 2026
First seen by InfoSec Signals
Oct 9, 2026

Affected products

Affected products
Juniper Networks Junos OS
juniper_networks:junos_os (from the name)
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
CNA record
juniper junos
juniper:junos
before 21.2; 21.2; 21.2; 21.2; 21.2; 21.2; 21.2; 21.2; and 70 more ranges
NVD

References

References

The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.

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