CVE-2026-87659

A critical authorization bypass vulnerability exists in the Management Server handling of Brocade Fabric OS versions before 10.0.1. A compromised switch connected to the fabric can transmit crafted inband Fibre Channel vendor-unique CT (Common Transport) management requests to bypass administrative authentication. Successful exploitation allows an unauthorized peer switch to execute administrative actions on the target device, including resetting administrative passwords, initiating system reboots, and triggering firmware downloads.

CVSS v3 9.8 CRITICAL

9.8^/10

CVSS v3 : CRITICAL

Vector :

Exploitability : 3.9 / Impact : 5.9

Attack Vector NETWORK

Attack Complexity LOW

Privileges Required NONE

User Interaction NONE

Confidentiality Impact HIGH

Integrity Impact HIGH

Availability Impact HIGH

Scope UNCHANGED

References

Link	Resource
https://support.broadcom.com/external/content/SecurityAdvisories/0/39153	Vendor Advisory

Configurations

Configuration 1 (hide)

cpe:2.3:o:broadcom:fabric_operating_system:*:*:*:*:*:*:*:*

History

13 Oct 2026, 17:25

Type	Values Removed	Values Added
CPE		cpe:2.3:o:broadcom:fabric_operating_system::::::::
First Time		Broadcom fabric Operating System Broadcom
References	~~() https://support.broadcom.com/external/content/SecurityAdvisories/0/39153 -~~	() https://support.broadcom.com/external/content/SecurityAdvisories/0/39153 - Vendor Advisory
CVSS	v2 : ~~unknown~~ v3 : ~~unknown~~	v2 : unknown v3 : 9.8

08 Oct 2026, 03:16

Type	Values Removed	Values Added
New CVE

Information

Published : 2026-10-08 03:16

Updated : 2026-10-13 17:25

NVD link : CVE-2026-87659

Mitre link : CVE-2026-87659

CVE.ORG link : CVE-2026-87659

JSON object : View

Products Affected

broadcom

fabric_operating_system

CWE

CWE-306

Missing Authentication for Critical Function

{"id": "CVE-2026-87659", "cveTags": [], "metrics": {"ssvcV203": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "ssvcData": {"id": "CVE-2026-87659", "role": "CISA Coordinator", "options": [{"exploitation": "none"}, {"automatable": "no"}, {"technicalImpact": "total"}], "version": "2.0.3", "timestamp": "2026-10-08T15:19:05.618383Z"}}], "cvssMetricV31": [{"type": "Primary", "source": "nvd@nist.gov", "cvssData": {"scope": "UNCHANGED", "version": "3.1", "baseScore": 9.8, "attackVector": "NETWORK", "baseSeverity": "CRITICAL", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H", "integrityImpact": "HIGH", "userInteraction": "NONE", "attackComplexity": "LOW", "availabilityImpact": "HIGH", "privilegesRequired": "NONE", "confidentialityImpact": "HIGH"}, "impactScore": 5.9, "exploitabilityScore": 3.9}], "cvssMetricV40": [{"type": "Secondary", "source": "sirt@brocade.com", "cvssData": {"Safety": "NOT_DEFINED", "version": "4.0", "Recovery": "NOT_DEFINED", "baseScore": 7.1, "Automatable": "NOT_DEFINED", "attackVector": "LOCAL", "baseSeverity": "HIGH", "valueDensity": "NOT_DEFINED", "vectorString": "CVSS:4.0/AV:L/AC:L/AT:P/PR:H/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X", "exploitMaturity": "NOT_DEFINED", "providerUrgency": "NOT_DEFINED", "userInteraction": "NONE", "attackComplexity": "LOW", "attackRequirements": "PRESENT", "privilegesRequired": "HIGH", "subIntegrityImpact": "NONE", "vulnIntegrityImpact": "HIGH", "integrityRequirement": "NOT_DEFINED", "modifiedAttackVector": "NOT_DEFINED", "subAvailabilityImpact": "NONE", "vulnAvailabilityImpact": "HIGH", "availabilityRequirement": "NOT_DEFINED", "modifiedUserInteraction": "NOT_DEFINED", "modifiedAttackComplexity": "NOT_DEFINED", "subConfidentialityImpact": "NONE", "vulnConfidentialityImpact": "HIGH", "confidentialityRequirement": "NOT_DEFINED", "modifiedAttackRequirements": "NOT_DEFINED", "modifiedPrivilegesRequired": "NOT_DEFINED", "modifiedSubIntegrityImpact": "NOT_DEFINED", "modifiedVulnIntegrityImpact": "NOT_DEFINED", "vulnerabilityResponseEffort": "NOT_DEFINED", "modifiedSubAvailabilityImpact": "NOT_DEFINED", "modifiedVulnAvailabilityImpact": "NOT_DEFINED", "modifiedSubConfidentialityImpact": "NOT_DEFINED", "modifiedVulnConfidentialityImpact": "NOT_DEFINED"}}]}, "affected": [{"source": "sirt@brocade.com", "affectedData": [{"vendor": "Brocade", "product": "Fabric OS", "versions": [{"status": "affected", "version": "0", "lessThan": "10.0.1", "versionType": "Brocade FabricOS"}], "defaultStatus": "unaffected"}]}], "published": "2026-10-08T03:16:35.820", "references": [{"url": "https://support.broadcom.com/external/content/SecurityAdvisories/0/39153", "tags": ["Vendor Advisory"], "source": "sirt@brocade.com"}], "vulnStatus": "Analyzed", "weaknesses": [{"type": "Secondary", "source": "sirt@brocade.com", "description": [{"lang": "en", "value": "CWE-306"}]}], "descriptions": [{"lang": "en", "value": "A critical authorization bypass vulnerability exists in the Management Server handling of Brocade Fabric OS versions before 10.0.1. A compromised switch connected to the fabric can transmit crafted inband Fibre Channel vendor-unique CT (Common Transport) management requests to bypass administrative authentication. Successful exploitation allows an unauthorized peer switch to execute administrative actions on the target device, including resetting administrative passwords, initiating system reboots, and triggering firmware downloads."}], "lastModified": "2026-10-13T17:25:28.650", "configurations": [{"nodes": [{"negate": false, "cpeMatch": [{"criteria": "cpe:2.3:o:broadcom:fabric_operating_system:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "B3B6713E-1D79-470C-97F0-DCFE4FD6B90A", "versionEndExcluding": "10.0.1"}], "operator": "OR"}]}], "sourceIdentifier": "sirt@brocade.com"}