Quick answer
Direct answer
Risk scores
| CVSS metric | What it means |
|---|---|
| Attack vector (AV:A) | Adjacent network |
| Attack complexity (AC:L) | Low complexity |
| Attack requirements (AT:N) | No attack requirements |
| Privileges required (PR:L) | Low privileges required |
| User interaction (UI:N) | No user interaction |
| Confidentiality (VC:H) | High confidentiality impact |
| Integrity (VI:H) | High integrity impact |
| Availability (VA:H) | High availability impact |
CVSS:4.0/AV:A/AC:L/AT:N/PR:L/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
About Broadcom Fabric Operating System
CVE-2026-87666 affects Broadcom Fabric Operating System, a product from Broadcom. Before acting, confirm where Broadcom Fabric Operating System runs in your estate, who owns it and whether it is reachable from the internet, because exposure decides real risk more than the score alone.
What the flaw is
In plain terms: An OS command injection vulnerability exists in the time and zone management subsystem of Brocade Fabric OS versions before 9.2.2d and 10.0.0 through 10.0.0a1. When updating system timezone settings via the REST API or configuration download routines, the system fails to sanitize input values before processing them in underlying shell execution routines. An authenticated user with low-privilege administrative access can exploit this vulnerability by submitting a crafted timezone string containing shell metacharacters. Successful exploitation allows the attacker to escape the restricted management environment and execute arbitrary shell commands with elevated privileges.
The weakness class is OS Command Injection. Untrusted input is passed to the operating system shell, letting an attacker run commands.
Based on its CVSS vector, the flaw needs local or adjacent access, needs some level of access, and needs no user interaction. Apply the vendor fix and confirm exposure on internet facing and business critical assets first.
Affected versions and timeline
| Field | Detail |
|---|---|
| Product | Broadcom Fabric Operating System |
| Affected versions | Fabric Operating System before 9.2.2d; Fabric Operating System from 10.0.0 before 10.0.1 |
| Published | Oct 8, 2026 |
| Last modified | Oct 14, 2026 |
| Added to CISA KEV | Not listed |
| Assigning CNA | sirt@brocade.com |
How to detect it
- Inventory every instance of Broadcom Fabric Operating System and record the running version against the affected range above.
- Check external attack surface scans for internet facing instances of the component.
- Review logs on affected systems for unusual requests, errors or new processes around the vulnerable function.
- Confirm with an authenticated vulnerability scan once your scanner has a check for this CVE.
How to fix it
- Apply the fixed version of Broadcom Fabric Operating System named in the vendor advisory.
- If patching must wait, restrict network access to the affected service and put it behind authentication or a web application firewall rule.
- Rescan after the change to prove the exposure is gone, then close the ticket.
CTEM action plan
| CTEM stage | What to do for this CVE |
|---|---|
| Scope | Add every business service that depends on Broadcom Fabric Operating System to the current CTEM cycle. |
| Discover | Find all instances, including shadow and cloud deployments, and record versions and exposure. |
| Prioritize | Rank using EPSS and CVSS together with asset exposure and business impact. |
| Validate | Confirm the flaw is reachable and exploitable in your environment and that compensating controls work. |
| Mobilize | Assign the fix to the asset owner with a due date matched to the priority, then verify closure. |
CWE References
- CWE-78: OS Command Injection More CVEs with this weakness
Technical References
Frequently asked questions
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