Strawberry GraphQL is a library for creating GraphQL APIs. 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 connectioninit handshake has been completed before processing start (subscription) messages. This allows a remote attacker to skip the onwsconnect authentication hook entirely by connecting with the graphql-ws subprotocol and sending a start message directly, without ever sending connectioninit. This vulnerability is fixed in 0.312.3.
{
"osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/35xxx/CVE-2026-35523.json",
"cwe_ids": [
"CWE-306"
],
"cna_assigner": "GitHub_M"
}{
"cpe": "cpe:2.3:a:strawberry:strawberry_graphql:*:*:*:*:*:python:*:*",
"source": [
"AFFECTED_FIELD",
"CPE_RANGE"
],
"extracted_events": [
{
"introduced": "0"
},
{
"fixed": "0.312.3"
}
]
}