CyberSecBulletin
CVE-2026-87684NVD status: Analyzed

Fabric OS: Stack-based Buffer Overflow

Published Updated By the CyberSecBulletin desk

CVE-2026-87684 is a critical-severity stack-based buffer overflow vulnerability in Fabric OS from Brocade, with a CVSS 3.1 base score of 9.8 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 0.58% chance of exploitation within 30 days, which is low compared with other CVEs.

Patch this week

Critical severity: a successful attack would have severe impact.

What to do

  1. Update Fabric OS to 10.0.1 or a later version.
  2. Update Fabric Operating System to 10.0.1 or a later version.
  3. Read the advisory on support.broadcom.com for workarounds and exact fixed builds.
  4. Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.

Affected products and versions

VendorProductAffected versionsFixed in
BrocadeFabric OSbefore 10.0.110.0.1
BroadcomFabric Operating Systembefore 10.0.110.0.1

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
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:N/UI:N/S:U/C:H/I:H/A:H. Scored by NVD.

Scoring systemScoreSeverityScored by
CVSS 4.08.7HighCNA (brocade.com)
CVSS 3.19.8CriticalNVD

Official description

A stack-based buffer overflow vulnerability exists in the SNMP daemon request handling of Brocade Fabric versions before 10.0.1. When processing an incoming SNMPv3 packet, an internal statistics gathering handler copies user-supplied context name data into a fixed-size buffer without properly validating the length of the string. A remote, unauthenticated attacker (under default configuration) can exploit this vulnerability by sending a specially crafted SNMPv3 packet, leading to memory corruption, daemon crash (Denial of Service), or potential arbitrary code execution.

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.

More Stack-based Buffer Overflow vulnerabilities (CWE-121)

Timeline

  1. CVE record published.
  2. CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: total).
  3. Record last changed materially (score, affected products, status or references).

References

Other vulnerabilities in Fabric OS

All Fabric OS vulnerabilities

Recent Stack-based Buffer Overflow vulnerabilities

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