CVE-2026-35523 HIGH

CVE-2026-35523: Authentication bypass in strawberry-graphql via legacy graphql-ws WebSocket subprotocol

Vendor Strawberry-Graphql
Product strawberry
Weakness CWE-306 · Missing auth
Published April 7, 2026
Last update April 9, 2026

CVSS base score

7.5/10
Attack vector Network
Attack complexity Low
Privileges required None
User interaction None
Confidentiality High
Integrity None

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

What the vulnerability does

01Description

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 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. This vulnerability is fixed in 0.312.3.

Key dates

02Disclosure timeline

April 7, 2026 CVE published
April 9, 2026 Record updated