[v2] @modelcontextprotocol/server 2.4.0 inlines fast-uri 3.1.8, which has 4 advisories published 2026-10-23 #3109

What happened?

Thanks for #3083 and 2.4.0: the bundled copy is now fast-uri 3.1.8, which clears the nine advisories in #2966.

On 2026-10-23, after 2.4.0 was published, GitHub published four more fast-uri advisories that affect 3.1.8 and are fixed in 3.1.9 (published 2026-10-19):

• GHSA-w74x-v6f9-j3xg (medium): URI scheme spoofing via percent-encoded scheme decoding
• GHSA-wjr9-j795-jxcr (medium): host confusion via unchecked WHATWG host canonicalization
• GHSA-xhq7-xmqj-769h (low): improper path equivalence in relative reference normalization
• GHSA-333x-w4r6-6crp (low): scheme injection via an unescaped first-segment colon in suffix references

As in #2966, ajv and its fast-uri are inlined into dist/ (noExternal in packages/server/tsdown.config.ts), so consumers cannot raise them with overrides or resolutions, and lockfile scanners do not see them. pnpm-lock.yaml on main still resolves fast-uri@3.1.8.

We have not checked whether any of these advisories is reachable through the SDK's use of ajv.

What did you expect?

A release whose bundled fast-uri is 3.1.9 or later.

Code to reproduce

npm pack @modelcontextprotocol/server@2.4.0
tar xzf modelcontextprotocol-server-2.4.0.tgz
grep -ho '#region ../../node_modules/.pnpm/[^/]*/' package/dist/*.mjs | sort -u
# prints, among others, .pnpm/ajv@8.18.0/ and .pnpm/fast-uri@3.1.8/

SDK version

@modelcontextprotocol/server 2.4.0

Area

Server