Fabric OS: Stack-based Buffer Overflow
CVE-2026-87665 is a high-severity stack-based buffer overflow vulnerability in Fabric OS from Brocade, with a CVSS 3.1 base score of 7.5 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. The record lists version 10.0.1 as the first without the flaw, so updating Fabric OS to that release or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 0.79% chance of exploitation within 30 days, higher than 57% of scored CVEs.
High severity with no evidence of exploitation so far.
What to do
- Update Fabric OS to 10.0.1 or a later version.
- Update Fabric Operating System to 10.0.1 or a later version.
- Read the advisory on support.broadcom.com for workarounds and exact fixed builds.
- Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Brocade | Fabric OS | before 10.0.1 | 10.0.1 |
| Broadcom | Fabric Operating System | before 10.0.1 | 10.0.1 |
Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.
How the severity score breaks down
- Attack vector
- NetworkCan be exploited remotely over a network, including the internet.
- Attack complexity
- LowNo special conditions are needed; the attack works reliably.
- Privileges required
- NoneNo account or login is needed.
- User interaction
- NoneNo action by a victim is required.
- Scope
- UnchangedImpact stays within the vulnerable component.
- Confidentiality
- NoneNo data is disclosed.
- Integrity
- NoneNothing can be modified.
- Availability
- HighThe component can be taken down completely.
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H. Scored by NVD.
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 4.0 | 6.0 | Medium | CNA (brocade.com) |
| CVSS 3.1 | 7.5 | High | NVD |
Official description
A stack-based buffer overflow vulnerability exists in the Internet Key Exchange (IKEv2) protocol handler on Brocade Fabric OS versions before 10.0.1. The vulnerability occurs when processing initial IKE key exchange requests on extension switches or blades running IPsec-enabled Fibre Channel over IP (FCIP) circuits. An unauthenticated remote attacker can exploit this vulnerability by sending a single, specifically crafted UDP packet (Port 500) containing an oversized Nonce payload. Successful exploitation results in a denial of service (data-plane process crash)
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Stack-based Buffer Overflow
The product writes past the end of a buffer that was allocated on the stack.
How developers prevent this class of flaw
- Use automatic buffer overflow detection mechanisms that are offered by certain compilers or compiler extensions. Examples include: the Microsoft Visual Studio /GS flag, Fedora/Red Hat FORTIFY_SOURCE GCC flag, StackGuard, and ProPolice, which provide various mechanisms including canary-based detection and range/index checking. D3-SFCV (Stack Frame Canary Validation) from D3FEND discusses canary-based detection in detail.
- Use an abstraction library to abstract away risky APIs. Not a complete solution.
- Implement and perform bounds checking on input.
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: partial).
- Record last changed materially (score, affected products, status or references).
References
Other vulnerabilities in Fabric OS
- 8.8 High severity
- 8.0 High severity
- 7.8 High severity
- 8.0 High severity
- 7.8 High severity
- 7.3 High severity
Recent Stack-based Buffer Overflow vulnerabilities
- 7.1 High severity
- 8.0 High severity
- 9.8 Critical severity
- 8.8 High severity
- 9.8 Critical severity
- 9.8 Critical severity
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