## What this does
Fixes an open redirect plus a handful of small, mostly-invisible
hardening changes around it.
## What's in it
- **The fix**: trailing-slash redirects no longer let `//evil.com/`
redirect off-host.
- **SSRF block** on the DNS/HTTP namespace verification — refuses to
dial loopback, RFC1918, link-local, multicast, CGNAT, or
IP-literal/single-label \"domains\".
- **Slow-client guard**: `ReadTimeout` and `IdleTimeout` on the HTTP
server (no `WriteTimeout` — would risk cutting off legitimate
multi-package publishes).
- **Defence-in-depth headers** on the UI (`/`) and 404 responses.
- **5xx responses** stop leaking raw DB error text to clients (logged
server-side instead).
- **Search filter** stops treating `%` and `_` as wildcards.
- **Validators**: PyPI/NuGet identifiers URL-escaped before fetching;
MCPB no longer follows redirects.
- **Misc**: `Version` field bounded to 255 chars; logs quote user input;
`BlockedNamespaces` denylist now catches subdomain claimants.
Each change is its own commit so they can be reviewed (or reverted)
independently.
## Test plan
- [ ] CI green
- [ ] Synthetic publish in staging for each package type (npm, pypi,
nuget, oci, mcpb) — confirms validator changes don't regress
- [ ] Quick browser check of `/` after deploy to confirm UI still loads
with the new CSP
- [ ] `curl https://<host>//evil.com/` — confirm the open redirect is
closed
🤖 Generated with [Claude Code](https://claude.com/claude-code)
---------
Co-authored-by: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
<!-- Provide a brief summary of your changes -->
## Motivation and Context
<!-- Why is this change needed? What problem does it solve? -->
This resolves
https://github.com/modelcontextprotocol/registry/issues/738. There are
two issues with the NuGet.org integration today:
1. Change the `registryBaseUrl` for NuGet to
`https://api.nuget.org/v3/index.json`. `https://api.nuget.org` is not
the entry point for our service and is not specific enough.
`https://api.nuget.org/v3/index.json` is the value that users put into
their tooling to connect to our public registry (it is installed by
default in .NET client tooling).
2. Use the service index API to get the URL pattern for package READMEs.
- This URL is not guaranteed to be stable. The service index URL
(`registryBaseUrl`) is, however.
Additionally, I polished up the error messages so various error modes
are clearer. When packages are published to NuGet.org, they take 2-5
minutes to become available due to validations we run.
Some possible states that are now handled and described more helpfully
are:
- Version exists, but the package has no README
- The ID exists, but the version does not
- The ID does not exist at all
There are only 3 authors (me, another MSFT person, and a community
member) explicitly setting the old value. The DB migration will fix the
issue. A future publish will fail with the validation error but the
error message is clear.
`registry type and base URL do not match: 'https://api.nuget.org' is not
valid for registry type 'nuget'. Expected:
https://api.nuget.org/v3/index.json`
## How Has This Been Tested?
<!-- Have you tested this in a real application? Which scenarios were
tested? -->
- Unit tests, new and existing
- Manual test locally
- Set old data in the DB, `docker compose up`, confirm the migration
updates the specific package
## Breaking Changes
Yes, but minimal impact expected, unless there is a dependency on the
specific `https://api.nuget.org` value downstream. I am not aware of any
such dependency, and the new value is more proper and specific.
## Types of changes
<!-- What types of changes does your code introduce? Put an `x` in all
the boxes that apply: -->
- [ ] Bug fix (non-breaking change which fixes an issue)
- [x] New feature (non-breaking change which adds functionality)
- [x] Breaking change (fix or feature that would cause existing
functionality to change)
- [x] Documentation update
## Checklist
<!-- Go over all the following points, and put an `x` in all the boxes
that apply. -->
- [x] I have read the [MCP
Documentation](https://modelcontextprotocol.io)
- [x] My code follows the repository's style guidelines
- [x] New and existing tests pass locally
- [x] I have added appropriate error handling
- [x] I have added or updated documentation as needed
## Additional context
<!-- Add any other context, implementation notes, or design decisions
-->
For more information about the NuGet API see:
https://learn.microsoft.com/en-us/nuget/api/overview#service-index (I
wrote most of the docs).
<!-- Provide a brief summary of your changes -->
Package identifier and version are required for some of the registries
else we won't be able to pull the meta data to validate the packages.
## Motivation and Context
<!-- Why is this change needed? What problem does it solve? -->
This is in continuation to
https://github.com/modelcontextprotocol/registry/pull/424
## How Has This Been Tested?
<!-- Have you tested this in a real application? Which scenarios were
tested? -->
Unit test.
## Breaking Changes
<!-- Will users need to update their code or configurations? -->
No
## Types of changes
<!-- What types of changes does your code introduce? Put an `x` in all
the boxes that apply: -->
- [ ] Bug fix (non-breaking change which fixes an issue)
- [ ] New feature (non-breaking change which adds functionality)
- [ ] Breaking change (fix or feature that would cause existing
functionality to change)
- [ ] Documentation update
## Checklist
<!-- Go over all the following points, and put an `x` in all the boxes
that apply. -->
- [ ] I have read the [MCP
Documentation](https://modelcontextprotocol.io)
- [ ] My code follows the repository's style guidelines
- [ ] New and existing tests pass locally
- [ ] I have added appropriate error handling
- [ ] I have added or updated documentation as needed
## Additional context
<!-- Add any other context, implementation notes, or design decisions
-->
Co-authored-by: Avish Porwal <avishporwal@microsoft.com>
Fixes#96
## Motivation and Context
See #96
## How Has This Been Tested?
Has some unit and integration tests, still needs proper testing of the
different registry types
## Breaking Changes
Yes, new package uploads will need extra verification
## Types of changes
<!-- What types of changes does your code introduce? Put an `x` in all
the boxes that apply: -->
- [ ] Bug fix (non-breaking change which fixes an issue)
- [x] New feature (non-breaking change which adds functionality)
- [x] Breaking change (fix or feature that would cause existing
functionality to change)
- [ ] Documentation update
