What’s Vulnerable › Vulnerabilities
CVE-2026-35526: Strawberry GraphQL affected by a Denial of Service via unbounded WebSocket subscriptions
- Severity: high (CVSS 7.5 v3.1)
- Exploited in the wild: not listed in CISA KEV
- EPSS: 0.3% probability of exploitation in the next 30 days
- Public exploit or detection template: none known
- Published: 2026-04-07 · updated 2026-06-17
- Weakness: CWE-770
Description
Strawberry GraphQL is a library for creating GraphQL APIs. Prior to 0.312.3, Strawberry GraphQL's WebSocket subscription handlers for both the graphql-transport-ws and legacy graphql-ws protocols allocate an asyncio.Task and associated Operation object for every incoming subscribe message without enforcing any limit on the number of active subscriptions per connection. An unauthenticated attacker can open a single WebSocket connection, send connection_init, and then flood subscribe messages with unique IDs. Each message unconditionally spawns a new asyncio.Task and async generator, causing linear memory growth and event loop saturation. This leads to server degradation or an OOM crash. This vulnerability is fixed in 0.312.3.
Affected products
- strawberry-graphql strawberry: before 0.312.3 — fixed in 0.312.3
How to fix
Upgrade to a fixed version: strawberry-graphql strawberry 0.312.3. Check the vendor advisory for mitigations.
References
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