CVE-2026-35523 Authentication bypass in strawberry-graphql via legacy graphql-ws WebSocket subprotocol
Attackers can bypass authentication on WebSocket subscription endpoints by using the legacy graphql-ws subprotocol without completing the handshake.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-35523?
CVE-2026-35523 is a high-severity authentication bypass vulnerability in strawberry-graphql strawberry, published on 7 Apr 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official 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.
Weakness: CWE-306
Which versions are affected by CVE-2026-35523?
3 open source packages ship an affected version, including strawberry-graphql. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
strawberry-graphql PyPI | All versions | 0.312.3 |
strawberry-graphql PyPI | All versions | 0.312.3 |
strawberry-graphql PyPI | All versions | 0.312.3 |
Products include Strawberry Strawberry Graphql.
How do I fix CVE-2026-35523?
Upgrade strawberry-graphql to 0.312.3 or later.
Upgrade, and rotate credentials and sessions that may have been exposed. More about Authentication bypass.
Is CVE-2026-35523 being exploited?
There is no known exploitation of CVE-2026-35523 in the wild and no public exploit code.
Other vulnerabilities in strawberry-graphql strawberry
- CVE-2026-35526 Strawberry GraphQL affected by a Denial of Service via unbounded WebSocket subscriptions
- CVE-2026-47706 Strawberry GraphQL has a Circular Fragment Reference DOS
- CVE-2026-47707 Strawberry GraphQL's Bypass of MaxAliasesLimiter via Fragment Spreads leading to GraphQL Alias Amplification
- CVE-2026-45739 Strawberry GraphQL: Default GraphiQL may expose HTTP headers in URLs
Sources
Also known as GHSA-vpwc-v33q-mq89, PYSEC-2026-133, ROOT-APP-PYPI-CVE-2026-35523.