dbcve.org
Improper Access ControlWeakness · CWE-284

CVE-2026-46416

MEDIUM · 6.3 CVSS v3.1 Published 2026-05-27
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
69/100
Remediation priority · Elevated
Remotely reachable Zero-click

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
Microsoft UFO open-source framework for intelligent automation across devices and platforms. In 3.0.1-4-ge2626659, Microsoft UFO creates one shared UFOWebSocketHandler instance and reuses it for multiple authenticated WebSocket connections. The handler stores per-connection protocol objects in mutable instance fields. Each new WebSocket connection overwrites those fields. Later, message handlers send responses through the shared fields instead of through protocol objects bound to the originating connection. As a result, the most recently connected authenticated client can receive protocol responses that belong to another authenticated client.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · high confidence

Microsoft UFO framework uses a single shared UFOWebSocketHandler instance for multiple authenticated WebSocket connections. The handler stores per-connection protocol objects in mutable instance fields that get overwritten with each new connection. Message handlers then send responses through these shared fields rather than the correct connection-bound protocol objects, causing the most recently connected client to potentially receive responses intended for another authenticated client.

MitigationFix the UFOWebSocketHandler to use connection-bound protocol objects instead of shared mutable instance fields, ensuring each WebSocket connection maintains its own isolated protocol state.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Privileges
Low
User interaction
None
Scope
Unchanged
Confidentiality
Low
Integrity
Low
Availability
Low

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:L

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Identify Microsoft UFO framework installation
    Search for UFO-related DLLs, packages, or modules in the application directory or dependency manifests (e.g., look for files containing 'UFO' or 'ufo' in assembly names, NuGet packages, or Python modules)
    Affected if The Microsoft UFO framework is present in the environment
  2. Check for WebSocket handler configuration
    Search for configuration files or code that references UFOWebSocketHandler, WebSocket endpoint definitions, or WebSocket routing configuration (e.g., look for 'UFOWebSocketHandler' string in config files, source code, or compiled binaries)
    Affected if UFOWebSocketHandler is configured or instantiated in the application
  3. Verify WebSocket connection handling
    Inspect the WebSocket connection establishment logic to determine if multiple authenticated connections share the same handler instance (review connection initialization code and handler lifecycle management)
    Affected if Multiple WebSocket connections are handled by a shared UFOWebSocketHandler instance
  4. Confirm authenticated WebSocket endpoints
    Review authentication middleware and WebSocket endpoint definitions to identify if authenticated clients establish WebSocket connections (check for [Authorize] attributes or authentication requirements on WebSocket routes)
    Affected if WebSocket endpoints require authentication and are accessible to authenticated users
  5. Check for message response routing
    Examine message handler code that processes incoming WebSocket messages and sends responses back to clients (look for code that references shared instance fields for protocol objects)
    Affected if Message handlers send responses through shared mutable instance fields rather than connection-specific protocol objects

A user is affected if the Microsoft UFO framework is deployed with authenticated WebSocket connections using a shared UFOWebSocketHandler instance that routes responses through shared mutable fields.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

From vendor data
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Fix the UFOWebSocketHandler to use connection-bound protocol objects instead of shared mutable instance fields, ensuring each WebSocket connection maintains its own isolated protocol state.

Have this fixed Scoped from the published advisory
  • Consultation3.0 h
  • Implementation8.0 h
  • Testing6.0 h
  • Review / QA3.0 h
20.0 hours of engineering $3,480
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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2026-46416 in production — separate from our analysis above.

No notes yet

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
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