An Out-of-bounds Write vulnerability in the routing protocol daemon (rpd) of Juniper Networks Junos OS and Junos OS Evolved allows an adjacent unauthenticated attacker to cause a denial of service when IS-IS link protection and backup-selection are configured.

Attack Vector Adjacent Network

Attack Complexity Low

Privileges Required None

Attack Requirements None

User Interaction None

Vulnerable System Confidentiality Impact Low

Vulnerable System Integrity Impact Low

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 Low

Integrity Impact Low

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

No data.

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 An Out-of-bounds Write vulnerability in the routing protocol daemon (rpd) of Juniper Networks Junos OS and Junos OS Evolved allows an adjacent unauthenticated attacker to cause a denial of service when IS-IS link protection and backup-selection are configured.
Title Junos OS and Junos OS Evolved: An out-of-bounds write causes an rpd crash when IS-IS backup selection is used
Weaknesses CWE-787
References
Metrics cvssV3_1

{'score': 7.6, 'vector': 'CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:H'}

cvssV4_0

{'score': 7.2, 'vector': 'CVSS:4.0/AV:A/AC:L/AT:N/PR:N/UI:N/VC:L/VI:L/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: 2026-10-14T16:56:54.480Z

Reserved: 2026-09-28T18:17:13.470Z

Link: CVE-2026-102177

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

Published: 2026-10-14T17:18:05.453

Modified: 2026-10-14T17:18:05.453

Link: CVE-2026-102177

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

No data.

Weaknesses