apollographql/apollo-server @apollo/server@5.5.0

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Minor Changes

• #8191 ada1200 Thanks @glasser! - ⚠️ SECURITY @apollo/server/standalone:

  Apollo Server now rejects GraphQL GET requests which contain a Content-Type header other than application/json (with optional parameters such as ; charset=utf-8). Any other value is now rejected with a 415 status code.

  (GraphQL GET requests without a Content-Type header are still allowed, though they do still need to contain a non-empty X-Apollo-Operation-Name or Apollo-Require-Preflight header to be processed if the default CSRF prevention feature is enabled.)

  This improvement makes Apollo Server's CSRF more resistant to browsers which implement CORS in non-spec-compliant ways. Apollo is aware of one browser which as of March 2026 has a bug which allows an attacker to circumvent Apollo Server's CSRF prevention feature to carry out read-only XS-Search-style CSRF attacks. The browser vendor is in the process of patching this vulnerability; upgrading Apollo Server to v5.5.0 mitigates this vulnerability.

  If your server uses cookies (or HTTP Basic Auth) for authentication, Apollo encourages you to upgrade to v5.5.0.

  This is technically a backwards-incompatible change. Apollo is not aware of any GraphQL clients which provide non-empty Content-Type headers with GET requests with types other than application/json. If your use case requires such requests, please file an issue and we may add more configurability in a follow-up release.

  See advisory GHSA-9q82-xgwf-vj6h for more details.