CyberSecBulletin
CVE-2026-85489NVD status: Analyzed

Brocade Active Support Connectivity Gateway: Missing Authentication for Critical Functionality

CVE-2026-85489 is a high-severity missing authentication for critical functionality vulnerability in Brocade Active Support Connectivity Gateway from Brocade, with a CVSS 3.1 base score of 8.8 out of 10. It can be exploited from the same local network by an unauthenticated attacker, without any action from a user. The record lists version 3.5.0 as the first without the flaw, so updating Brocade Active Support Connectivity Gateway to that release or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 0.21% chance of exploitation within 30 days, which is low compared with other CVEs.

Next patch cycle

High severity with no evidence of exploitation so far.

What to do

  1. Update Brocade Active Support Connectivity Gateway to 3.5.0 or a later version.
  2. Read the advisory on support.broadcom.com for workarounds and exact fixed builds.

Affected products and versions

VendorProductAffected versionsFixed in
BrocadeBrocade Active Support Connectivity Gatewaybefore 3.5.03.5.0

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
AdjacentThe attacker must be on the same local network segment.
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:A/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 3.18.8HighNVD

Official description

An authentication flaw exists in the Brocade ASCG administrative management service component. An unauthenticated network user can issue direct API requests to perform privileged actions, including accessing sensitive system configuration mapping data, modifying managed device inventories, and altering operational settings. This vulnerability affects all versions of Brocade ASCG before 3.5.0.

Source: the CVE record as published by its numbering authority, via NVD and CVE.org.

The underlying weakness: Missing Authentication for Critical Functionality

The product does not perform any authentication for functionality that requires a provable user identity or consumes a significant amount of resources.

How developers prevent this class of flaw

  • For any security checks that are performed on the client side, ensure that these checks are duplicated on the server side, in order to avoid CWE-602. Attackers can bypass the client-side checks by modifying values after the checks have been performed, or by changing the client to remove the client-side checks entirely. Then, these modified values would be submitted to the server.
  • Use a vetted library or framework that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid. For example, consider using libraries with authentication capabilities such as OpenSSL or the ESAPI Authenticator.
  • When storing data in the cloud (e.g., S3 buckets, Azure blobs, Google Cloud Storage, etc.), use the provider's controls to require strong authentication for users who should be allowed to access the data.

More Missing Authentication for Critical Functionality vulnerabilities (CWE-306)

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 Brocade Active Support Connectivity Gateway

All Brocade Active Support Connectivity Gateway vulnerabilities

Recent Missing Authentication for Critical Functionality vulnerabilities

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