CVE-2026-87674 is a high severity local privilege escalation flaw in Brocade Fabric OS, scored 7.8. Boundaries imply 9.2.2d or later, or a release after 10.0.0a1. Check your installed version against the affected list below, then patch or restrict access until you can. The record does not flag it as exploited.
What's affected
- Brocade Fabric OS before 9.2.2d.
- Brocade Fabric OS 10.0.0 through 10.0.0a1.
Severity in the record: High (7.8), vector CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H. Weakness: CWE-78.
Fix: Boundaries imply 9.2.2d or later, or a release after 10.0.0a1. Confirm in the advisory. The record gives the affected range only. The exact fixed builds are listed in the Broadcom advisory, which you should read before scheduling the upgrade.
How to check if you're exposed
- Fabric OS exposes its running version from the switch command line. The
firmwareshowcommand is the usual way to read it; confirm the command and output format against your Fabric OS release documentation. - Repeat on every switch, director and extension blade, since versions can differ across a fabric.
- Compare each version with the affected range above and with the fixed builds named in the Broadcom advisory.
Run these on every affected device, including ones in remote sites, labs and spares that are powered on.
What to do now
- Confirm the version of every affected system using the checks above.
- Read the vendor advisory linked in Sources and note the fixed version for your release line.
- Schedule the update, starting with systems that face untrusted networks or hold the most sensitive data.
- In the meantime: limit local shell access to people who need it.
- Record the change, then recheck the version to confirm it took effect.
Why it matters
Access controls on internal inter-process communication channels of the logging daemon are too weak. An unprivileged local user can submit malformed logging configuration, and because the generated configuration file is not sanitized, injected directives run with elevated privileges when the service reloads. The record lists no CWE for this CVE. The impact is local privilege escalation, so the attacker first needs a local login.
The record's KEV flag is false, so this post makes no claim that the flaw is exploited in the wild. That can change, so recheck the CISA catalog from time to time.
Network and management devices are patched less often than servers, because upgrades mean planned downtime. That gap is where a flaw like this stays open longest, so build the version check into your regular inventory.
The vector string in the record is a compact summary of how the flaw is reached and what it costs. AV is the attack vector (network, adjacent or local), PR is the privilege the attacker needs, and the C, I and A letters give the impact on confidentiality, integrity and availability. Read it against your own network layout rather than relying on the score alone.
After you patch
Patching is not the end of the job. Recheck the version on each system, because an upgrade that failed or rolled back looks the same as a success until someone looks. Keep the advisory link with your change record so the next reviewer can see why the update happened.
If you cannot patch soon, write down the reason, the compensating control you chose and a date to revisit. Exceptions without a date tend to become permanent.
Quick check
Can this be exploited remotely?
The vector in the record is local (AV:L). The attacker needs a local account first.
Sources
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Broadcom advisory: 39145
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Safeguard Gold: CVE-2026-87674
Last reviewed: 18 October 2026.
