CVE-2026-107727 PUBLISHED

Strawberry legacy graphql-ws retains naturally completed subscription slots

Assigner: GitHub_M
Reserved: 08.10.2026 Published: 08.10.2026 Updated: 08.10.2026

Strawberry GraphQL is a library for creating GraphQL APIs. From 0.312.3 until 0.327.2, the legacy graphql-ws subscription handler in strawberry/subscriptions/protocols/graphql_ws/handlers.py does not remove naturally completed operations from self.tasks and self.subscriptions. When max_subscriptions_per_connection is configured, a client on a persistent WebSocket connection can use distinct operation IDs for one-shot subscriptions to fill the connection's configured slots even after those subscriptions send complete, causing later legitimate operations on that connection to be rejected with Subscription limit reached. The modern graphql-transport-ws protocol and deployments without the configured per-connection cap are not affected. This issue is fixed in version 0.327.2.

Metrics

CVSS Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L
CVSS Score: 3.7

Product Status

Vendor strawberry-graphql
Product strawberry
Versions
  • Version >= 0.312.3, < 0.327.2 is affected

References

Problem Types

  • CWE-400: Uncontrolled Resource Consumption CWE