CVE-2026-35523CWE-306

Authentication bypass in strawberry-graphql via legacy graphql-ws WebSocket subprotocol

High · published April 7, 2026

CVSS v3.1
7.5
EPSS
1%
Percentile
48.0
In the wild
Unconfirmed
What it is

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.

The record
Technical detail
CVSS v3.1
7.5 · HIGH
Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
CVSS v4.0
Not supplied
EPSS
0.00598 · 48.0th percentile
Weakness
CWE-306 · Missing Authentication for Critical Function
Published
2026-04-07T15:58Z
EPSS history
Timeline
  • 07 APR 15:58Z
    Authentication bypass in strawberry-graphql via legacy graphql-ws WebSocket subprotocol
    cvelistv5