Vulnerability · Published Apr 7, 2026 · Assigned by GitHub_M
CVE-2026-35526Strawberry GraphQL affected by a Denial of Service via unbounded WebSocket subscriptions
High 7.5
In plain English
A high-severity resource allocation without limits in strawberry from strawberry-graphql. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.3% (higher than 21% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official 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 packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| PyPI | strawberry-graphql | 0.312.3 | GHSA-hv3w-m4g2-5x77 |
| PyPI | strawberry-graphql | 0.312.3 | PYSEC-2026-134 |
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| strawberry-graphql | strawberry | < 0.312.3 |
Weakness: CWE-770 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H