mcp-gateway-registry: review destinations that survived the upgrade
A patched version and an approved catalog are separate deliverables. Reconcile existing destinations before closing the change.
Auf Portugiesisch lesenBy Pentesty
The component and the change
AWS bulletin 2026-180-AWS concerns mcp-gateway-registry, an operator-deployed open-source project. CVE-2026-125926 lets an authenticated user authorized to register or modify servers trigger internal requests. Versions 1.0.3 through 1.34.0 are affected; 1.35.0 validates destinations during registration and editing, leaving earlier configurations unchanged.
The plan below is a proposed acceptance exercise for a deployment you operate. First identify the running process, its image and the corresponding repository. Ask the environment owner to associate that identity with the approved change, so a similar product name does not determine the response scope by itself.
Compare intent with configuration
Prepare a controlled catalog export and choose an integration that matters to the business. Describe the service that should receive its calls, the team maintaining it and the information it should return. Compare that description with the configuration actually loaded. An old inventory spreadsheet is a reference to check rather than an accepted answer.
Classify differences before changing them. An address might represent a legitimate migration, a forgotten test environment or an integration without a current purpose. Send each difference to the service owner. The decision should explain the connectivity requirement, including when the answer is to remove an item from the catalog temporarily.
Use a synthetic migration as the exercise
In an authorized staging environment, propose two synthetic records, one created before the change and another afterward. Both should point to test services controlled by the team. Compare administrative creation, configuration persistence and the resulting request. Agree in advance which results would require the team to stop the exercise.
Do not use metadata addresses, real credentials or third-party services as validation targets. A synthetic receiver can record the test identifier and return harmless content. The proposed objective is to distinguish stored state from the rule applied to an edit, using a comparison that another reviewer can reproduce without production access.
Make exceptions part of the product
Imagine a billing connector that depends on an unusual internal route. Blocking it without consulting finance could disrupt closing; retaining it simply because it always existed could preserve unnecessary exposure. Request an alternative, a justification for retaining the route and a concrete condition for retiring the exception later.
Include an ownership handover and connector retirement in the exercise. Who receives the request, what configuration changes and how does the requester notice withdrawal? This simulation helps assess the integration lifecycle. Initial registration is only one administrative decision that must work predictably when the business or the supporting team changes.
Separate investigation from operational acceptance
If an unexplained record appears, preserve the observed configuration before removal and refer the question to incident response. Do not turn staging acceptance into an attempt to prove retrospectively what happened. The response team will need to assess the available history and identify the questions that history cannot answer reliably.
To close the change, deliver the reviewed destination list, resolved differences and remaining approved exceptions. Include exercises that could not be completed and explain their effect on the decision. Useful acceptance describes permitted connectivity and its limitations, enabling operations to maintain the catalog after the upgrade instead of inheriting an unexplained snapshot.
Frequently asked questions
Is the installed version enough to close the work?
Use the version as one piece of change evidence. The proposed acceptance also requires reviewing the catalog and resolving differences with integration owners.
How can testing avoid sensitive services?
Agree on synthetic receivers and data in the authorized environment. Define the expected result before starting and stop the exercise if it crosses that boundary.
Must every difference be removed immediately?
Assess its purpose and operational consequence. An exception may require containment or a planned migration; the decision needs a justification and an explicit condition for closure.
Does this prove there was no earlier incident?
No. The exercise evaluates the proposed behavior of a change. Historical investigation depends on other evidence and should state its uncertainties separately.
Sources and references
Original Pentesty analysis, published November 12, 2026. The proposed scenarios are editorial guidance, with scope and validation to be defined for each environment.