CVE-2026-87424

Authentication bypass via shared JWT signing key

Published Oct 8, 2026 · Updated Oct 8, 2026

Authentication bypass in Brocade ASCG before 3.5.0 allows attackers to access the SupportLink API using a shared cryptographic key. The API's JWT HMAC signing key is hardcoded across deployments, undermining authentication isolation between installations. Standard deployments are affected, and exploitation requires adjacent-network access and low privileges; specific unauthorized API operations are not disclosed.

CVSS severity8.6
High
EPSS probability0.19%
Next 30 days · Oct 19, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Authentication bypass in Brocade ASCG before 3.5.0 allows attackers to access the SupportLink API using a shared cryptographic key. The API's JWT HMAC signing key is hardcoded across deployments, undermining authentication isolation between installations. Standard deployments are affected, and exploitation requires adjacent-network access and low privileges; specific unauthorized API operations are not disclosed.

The record

CVE
CVE-2026-87424
Published
Oct 8, 2026
Updated
Oct 8, 2026
Vendor
Brocade Communications Systems
Product
Brocade Active Support Connectivity Gateway
Classifications
CWE-321, T1606
Attack vector
adjacent
Privileges
authenticated

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 <3.5.0

What conditions does exploitation require?

Attack vectoradjacent
Required privilegesauthenticated

What is affected?

Brocade Communications Systems · Brocade Active Support Connectivity Gatewayversion=0 <3.5.0

Published CVSS scores

8.6BroadcomCVSS:4.0/AV:A/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/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
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-321Use of Hard-coded Cryptographic Key
T1606Forge Web Credentials

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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