CVE-2026-87665

Data-plane crash via oversized IKEv2 Nonce

Published Oct 8, 2026 · Updated Oct 8, 2026

Stack-based buffer overflow in the IKEv2 handler of Brocade Fabric OS before 10.0.1 allows remote attackers to crash its data-plane process. The handler processes an oversized Nonce payload in an initial IKE key exchange UDP packet without sufficient bounds enforcement, overwriting stack memory. Exploitation requires an extension switch or blade with an IPsec-enabled FCIP circuit reachable on UDP port 500; the reported consequence is a process crash.

CVSS severity6.0
Medium
EPSS probability0.79%
Next 30 days · Oct 19, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Stack-based buffer overflow in the IKEv2 handler of Brocade Fabric OS before 10.0.1 allows remote attackers to crash its data-plane process. The handler processes an oversized Nonce payload in an initial IKE key exchange UDP packet without sufficient bounds enforcement, overwriting stack memory. Exploitation requires an extension switch or blade with an IPsec-enabled FCIP circuit reachable on UDP port 500; the reported consequence is a process crash.

The record

CVE
CVE-2026-87665
Published
Oct 8, 2026
Updated
Oct 8, 2026
Vendor
Brocade Communications Systems
Product
Fabric OS
Classifications
CWE-121, T1499.004
Attack vector
adjacent
Privileges
unauthenticated

Timeline

How it unfolded

  1. Oct 8, 2026CVE publishedPublication date reported by the CVE source.
  2. Oct 8, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=0 <10.0.1

What conditions does exploitation require?

Attack vectoradjacent
Required privilegesunauthenticated

What is affected?

Brocade Communications Systems · Fabric OSversion=0 <10.0.1

Published CVSS scores

6.0Brocade Communications SystemsCVSS:4.0/AV:A/AC:L/AT:P/PR:N/UI:N/VC:N/VI:L/VA:H/SC:N/SI:N/SA:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Activity data is delayed. The latest report is Sep 28, 2026.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 22, 2026Sep 28, 2026
Latest reporting daySep 28, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectoradjacent
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-121Stack-based Buffer Overflow
T1499.004Endpoint Denial of Service: Application or System Exploitation

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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