CVE-2026-87659: fabric operating Missing Auth — Fix

Description

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.

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CVSS v3.1 Score

9.8

CRITICAL

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

EPSS — Exploit Prediction

0.0024

Probability of exploitation

0.15%

Percentile rank

EPSS estimates the probability that this vulnerability will be exploited in the wild within the next 30 days. A higher score means more likely to be exploited.

Weakness Type (CWE)

CWE-306 Missing Authentication

Affected Products

Vendor	Product	Versions
broadcom	fabric_operating_system	< 10.0.1

References

Advisories & Patches

https://support.broadcom.com/external/content/SecurityAdvisories/0/39153

Frequently Asked Questions

What is 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. It has a CVSS v3.1 base score of 9.8 (CRITICAL).

How severe is CVE-2026-87659? +

CVE-2026-87659 has a CVSS v3.1 score of 9.8 out of 10, rated CRITICAL. This is a critical vulnerability that should be patched immediately. The EPSS score is 0.0024, placing it in the 0th percentile for exploitation probability.

What products are affected by CVE-2026-87659? +

CVE-2026-87659 affects products from broadcom, specifically: fabric_operating_system. Check the affected products table above for specific version ranges.

How do I check if I'm vulnerable to CVE-2026-87659? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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