CVE-2026-35523
strawberry-graphql: Authentication bypass via legacy graphql-ws WebSocket subprotocol
Description
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.
How to fix CVE-2026-35523
To remediate CVE-2026-35523, upgrade the affected package to a fixed version below.
- —upgrade to 0.312.3 or later
- —upgrade to 0.312.3 or later
Is CVE-2026-35523 being exploited?
Low — EPSS is 0.1%, meaning exploitation activity has not been observed at scale.
Affected packages (2)
- from 0, < 0.312.3
- from 0, < 0.312.3
CVSS scores
| Source | Version | Severity | Vector |
|---|---|---|---|
| osv | CVSS 3.1 | HIGH7.5 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N |