CVE-2026-35523 is a high-severity (CVSS 7.5) Missing Authentication vulnerability in strawberry-graphql. A fix is available for strawberry-graphql — see the affected versions and patch details below.
Authentication bypass in strawberry-graphql via legacy graphql-ws WebSocket subprotocol
Exploitation Status
No confirmed exploitation observed yet
- CISA assesses this as automatable — exploitation doesn’t require manual, per-target effort, which raises the odds of mass scanning and opportunistic attacks.
- CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.
Exploitation and automatability from CISA’s SSVC triage for CVE-2026-35523.
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
How urgent is this, really
Where this sits among everything scored
Real-World Exposure
strawberry-graphqlReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects PyPI packages — download data is not available via public APIs for these ecosystems.
Description
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.
The graphql-transport-ws subprotocol handler is not affected, as it correctly gates subscription operations on a connection_acknowledged flag. However, both subprotocols are enabled by default in all framework integrations that support websockets, and the subprotocol is selected by the client via the Sec-WebSocket-Protocol header.
Any application relying on on_ws_connect for authentication or authorization is affected.
Mitigation: Upgrade to the patched version, or explicitly disable the legacy graphql-ws subprotocol by setting subscription_protocols=[GRAPHQL_TRANSPORT_WS_PROTOCOL] on your GraphQL view/router.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐍PyPI | strawberry-graphql | all versions | 0.312.3pip install --upgrade 'strawberry-graphql==0.312.3' |
Affected Products
strawberry graphqlstrawberryDetection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for strawberry-graphql, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update strawberry-graphql to 0.312.3 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-35523 is resolved across your whole dependency graph.
Workarounds
Put an independent control in front of the weakness: restrict the affected endpoint or interface to trusted networks, require an additional authentication factor or proxy-level check, and invalidate existing sessions and credentials in case the flaw has already been used.
Frequently Asked Questions
Is CVE-2026-35523 in your dependencies?
Find it across PyPI, including transitive dependencies.