Fabric OS: Heap-based Buffer Overflow
CVE-2026-87679 is a high-severity heap-based buffer overflow vulnerability in Fabric OS from Brocade, with a CVSS 3.1 base score of 7.2 out of 10. It can be exploited remotely over the network by an attacker with administrator privileges, 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 0.36% chance of exploitation within 30 days, which is low compared with other 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.
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
- HighAdministrator-level access is required first.
- User interaction
- NoneNo action by a victim is required.
- Scope
- UnchangedImpact stays within the vulnerable component.
- Confidentiality
- HighAll data handled by the component can be read.
- Integrity
- HighData or code can be modified at will.
- Availability
- HighThe component can be taken down completely.
Vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H. Scored by NVD.
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 4.0 | 8.5 | High | CNA (brocade.com) |
| CVSS 3.1 | 7.2 | High | NVD |
Official description
When Brocade Fabric OS versions before 10.0.1 processes trunk configuration operations, the application parses user-supplied list strings into dynamically allocated heap arrays without enforcing boundary checks on the maximum allowable number of elements. An authenticated administrator can exploit this vulnerability via crafted REST API requests containing an excessive number of list delimiters, causing heap corruption that can result in service crash or arbitrary code execution.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Heap-based Buffer Overflow
The product writes past the end of a buffer that was allocated on the heap.
How developers prevent this class of flaw
- Pre-design: Use a language or compiler that performs automatic bounds checking.
- Use an abstraction library to abstract away risky APIs. Not a complete solution.
- 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.
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: total).
- 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 Heap-based Buffer Overflow vulnerabilities
- 9.8 Critical severity
- 9.8 Critical severity
- 7.8 High severity
- 7.5 High severity
- 9.8 Critical severity
- 8.1 High severity
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