A Reachable Assertion vulnerability in the l2ald daemon of Juniper Networks Junos OS and Junos OS Evolved allows an attacker with access to a configured ICCP peer to cause a denial of service via a malformed MC-LAG message.

Attack Vector Adjacent Network

Attack Complexity Low

Privileges Required None

Attack Requirements None

User Interaction None

Vulnerable System Confidentiality Impact None

Vulnerable System Integrity Impact None

Vulnerable System Availability Impact High

Subsequent System Confidentiality Impact None

Subsequent System Integrity Impact None

Subsequent System Availability Impact Low

Attack Vector Adjacent Network

Attack Complexity Low

Privileges Required None

Scope Unchanged

Confidentiality Impact None

Integrity Impact None

Availability Impact High

User Interaction None

No CVSS v3.0

No CVSS v2

This CVE is not in the KEV list.

No EPSS score available.

Key SSVC decision points have not yet been added.

Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).

Vendor Product Default status Versions
Juniper Networks Junos OS unaffected
Version Status Constraints
0 affected < 23.2R2-S7.7
23.4 affected < 23.4R2-S8.13
24.2 affected < 24.2R2-S5.5
24.4 affected < 24.4R2-S5
25.2 affected < 25.2R2-S2
25.4 affected < 25.4R1-S3
26.2 affected < 26.2R1-S2
Juniper Networks Junos OS Evolved unaffected
Version Status Constraints
0 affected < 23.2R2-S7.7-EVO
23.4 affected < 23.4R2-S8.11-EVO
24.2 affected < 24.2R2-S5.6-EVO
24.4 affected < 24.4R2-S5-EVO
25.2 affected < 25.2R2-S2-EVO
25.4 affected < 25.4R1-S3-EVO
26.2 affected < 26.2R1-S2-EVO
23.4X100 affected —
25.2X100 affected < 25.2X100-D35-EVO
25.4X300 affected < 25.4X300-D40-EVO

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Project Subscriptions

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Advisories

No advisories yet.

Fixes

Solution

The following software releases have been updated to resolve this specific issue: Junos OS: 23.2R2-S7.7, 23.4R2-S8.13, 24.2R2-S5.5, 24.4R2-S5, 25.2R2-S2, 25.4R1-S3, 25.4R2, 26.2R1-S2, 26.2R2, 26.4R1, and all subsequent releases. Junos OS Evolved: 23.2R2-S7.7-EVO, 23.4R2-S8.11-EVO, 24.2R2-S5.6-EVO, 24.4R2-S5-EVO, 25.2R2-S2-EVO, 25.2X100-D35-EVO, 25.4R1-S3-EVO, 25.4R2-EVO, 25.4X300-D40-EVO, 26.2R1-S2-EVO, 26.2R2-EVO, 26.4R1-EVO, and all subsequent releases. Note: For Junos OS releases 23.2, 23.4, and 24.2, and Junos OS Evolved releases 23.2-EVO, 23.4-EVO, and 24.2-EVO, specific respins have been referenced. Previously published versions of these releases have been rebuilt to resolve the security vulnerabilities identified in this advisory.

Workaround

There are no known workarounds for this issue.

References
Link Providers
https://supportportal.juniper.net/JSA112187 cve-icon cve-icon
History

Wed, 14 Oct 2026 17:00:00 +0000

Type Values Removed Values Added
Description A Reachable Assertion vulnerability in the l2ald daemon of Juniper Networks Junos OS and Junos OS Evolved allows an attacker with access to a configured ICCP peer to cause a denial of service via a malformed MC-LAG message.
Title Junos OS and Junos OS Evolved: An attacker causes l2ald to restart when MC-LAG ICCP MAC synchronization is enabled
Weaknesses CWE-617
References
Metrics cvssV3_1

{'score': 6.5, 'vector': 'CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H'}

cvssV4_0

{'score': 7.1, 'vector': 'CVSS:4.0/AV:A/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:L/AU:Y/R:A/V:C/RE:M'}

Projects

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cve-icon MITRE

Status: PUBLISHED

Assigner: juniper

Published:

Updated: 2026-10-14T20:15:52.210Z

Reserved: 2026-09-28T17:33:49.411Z

Link: CVE-2026-102034

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

Published: 2026-10-14T17:17:57.370

Modified: 2026-10-14T21:17:28.513

Link: CVE-2026-102034

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

No data.

Weaknesses