Junos
CVE-2026-21912
MEDIUM
Severity by source
AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Primary rating from NVD · only source for this CVE.
CVSS VectorNVD
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Lifecycle Timeline
2DescriptionCVE.org
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.
AnalysisAI
A race condition in Juniper Junos OS on MX10k Series with LC480 or LC2101 line cards allows low-privileged local users to crash line card and potentially chassis daemons by repeatedly executing the 'show system firmware' command. Affected versions include all releases before 21.2R3-S10 and multiple later branches up to 23.2R, with no patch currently available. This denial of service vulnerability requires local access and can be triggered without elevated privileges.
Technical ContextAI
Affects Junos. 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
RemediationAI
Monitor vendor advisories for a patch.
named in ISC BIND 9.x before 9.9.8-P4 and 9.10.x before 9.10.3-P4 does not properly handle DNAME records when parsing fe
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A PHP External Variable Modification vulnerability in J-Web of Juniper Networks Junos OS on EX Series and SRX Series all
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Juniper Junos 11.4 before R11, 12.1 before R9, 12.1X44 before D30, 12.1X45 before D20, 12.1X46 before D15, 12.1X47 befor
NFX Series devices using Juniper Networks Junos OS are susceptible to a local command execution vulnerability thereby al
NFX Series devices using Juniper Networks Junos OS are susceptible to a local code execution vulnerability thereby allow
Insufficient validation of environment variables in the telnet client supplied in Junos OS can lead to stack-based buffe
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On QFX10000 Series devices using Juniper Networks Junos OS when configured as transit IP/MPLS penultimate hop popping (P
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An Uncontrolled Memory Allocation vulnerability leading to a Heap-based Buffer Overflow in the packet forwarding engine
Same technique Denial Of Service
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External POC / Exploit Code
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