{"id":"CVE-2026-35523","aliases":["GHSA-vpwc-v33q-mq89","PYSEC-2026-133"],"url":"https://o3.security/vulnerability/CVE-2026-35523","summary":"Authentication bypass in strawberry-graphql via legacy graphql-ws WebSocket subprotocol","details":"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`.\n\nThe 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.\n\nAny application relying on `on_ws_connect` for authentication or authorization is affected.\n\nMitigation: 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.","published":"2026-04-07T15:58:17.694Z","modified":"2026-08-12T03:51:08.954627285Z","cvss":{"score":7.5,"severity":"HIGH","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N"},"epss":null,"cisaKev":null,"exploitsKnown":0,"affectedPackages":[{"ecosystem":"PyPI","name":"strawberry-graphql","fixedVersion":"0.312.3"}],"fix":{"url":"https://github.com/strawberry-graphql/strawberry/commit/0977a4e6b41b7cfe3e9d8ba84a43458a2b0c54c2","label":"strawberry-graphql/strawberry@0977a4e"},"references":[{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/35xxx/CVE-2026-35523.json"},{"type":"ADVISORY","url":"https://github.com/strawberry-graphql/strawberry/security/advisories/GHSA-vpwc-v33q-mq89"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-35523"},{"type":"WEB","url":"https://github.com/strawberry-graphql/strawberry/commit/0977a4e6b41b7cfe3e9d8ba84a43458a2b0c54c2"},{"type":"WEB","url":"https://github.com/pypa/advisory-database/tree/main/vulns/strawberry-graphql/PYSEC-2026-133.yaml"},{"type":"PACKAGE","url":"https://github.com/strawberry-graphql/strawberry"},{"type":"WEB","url":"https://github.com/strawberry-graphql/strawberry/releases/tag/0.312.3"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-08-12T03:51:08.954627285Z"}}