GitHub Advisoryadvisory · PyPI
GHSA-vpwc-v33q-mq89 strawberry-graphql: Authentication bypass via legacy graphql-ws WebSocket subprotocol
HIGH
Official page ↗
- Aliases
- CVE-2026-35523
- Ecosystem
- PyPI
- Packages
- strawberry-graphql
- Severity
- High
- CVSS vector
- CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
- Weaknesses
- CWE-306
- Reviewed
- 2026-04-06
Affected packages
• PyPI strawberry-graphql: < 0.312.3 → fixed in 0.312.3
Description
Strawberry up until version `0.312.3` is vulnerable to an authentication bypass on WebSocket subscription endpoints. The legacy graphql-ws subprotocol handler does not verify that a `connection_init` handshake has been completed before processing start (subscription) messages. This allows a remote attacker to skip the `on_ws_connect` authentication hook entirely by connecting with the graphql-ws subprotocol and sending a start message directly, without ever sending `connection_init`.
The graphql-transport-ws subprotocol handler is not affected, as it correctly gates subscription operations on a connection_acknowledged flag. However, both subprotocols are enabled by default in all framework integrations that support websockets, and the subprotocol is selected by the client via the Sec-WebSocket-Protocol header.
Any application relying on `on_ws_connect` for authentication or authorization is affected.
Mitigation: Upgrade to the patched version, or explicitly disable the legacy graphql-ws subprotocol by setting `subscription_protocols=[GRAPHQL_TRANSPORT_WS_PROTOCOL]` on your GraphQL view/router.
Related
Alias · CVE (1)
- CVE-2026-35523 Strawberry GraphQL is a library for creating GraphQL APIs. vulnerability
Weakness · CWE (1)
- CWE-306 Missing Authentication for Critical Functionality weakness
References
- https://github.com/strawberry-graphql/strawberry/security/advisories/GHSA-vpwc-v33q-mq89 web
- https://nvd.nist.gov/vuln/detail/CVE-2026-35523 advisory
- https://github.com/strawberry-graphql/strawberry/commit/0977a4e6b41b7cfe3e9d8ba84a43458a2b0c54c2 web
- https://github.com/pypa/advisory-database/tree/main/vulns/strawberry-graphql/PYSEC-2026-133.yaml web
- https://github.com/strawberry-graphql/strawberry package
- https://github.com/strawberry-graphql/strawberry/releases/tag/0.312.3 web