Submit #811406: vercel ai @ai-sdk/[email protected] Uncontrolled Resource Consumption (CWE-400)

# Technical Details
An Uncontrolled Resource Consumption DoS vulnerability exists in the `createJsonResponseHandler` method in `packages/provider-utils/src/response-handler.ts` of vercel/ai.

The application fails to constrain buffer accumulation when handling standard JSON inferences from backing AI providers or MCP servers. A malicious provider entity streaming infinite whitespace without a `Content-Length` header bypasses network constraints and crashes the entire backend service via a native V8 memory engine exhaustion.

# Vulnerable Code
File: packages/provider-utils/src/response-handler.ts
Method: createJsonResponseHandler
Why: Non-streaming standard JSON retrievals utilize `await response.text()` and `await safeParseJSON()` natively across HTTP sockets without imposing fixed size-limits (like the bounded `readResponseWithSizeLimit()` method logic missing on these pathways).

# Reproduction
1. Operate an explicit pseudo-endpoint server mapping the mocked AI chat routes that returns a generic JSON structure chunking an infinite stream of byte whitespace without dropping the TCP socket.
2. Initialize an AI SDK gateway specifying the malicious local address as its `baseURL`.
3. Submit a generation request targeting the AI API. As the network engine continuously aggregates data to evaluate the JSON object, Native V8 memory heap bounds are exhausted.

# Impact
- High-Impact Application DoS: Terminates the backend architecture processes causing total cluster outage.
- Disrupts multi-tenant integration pipelines that facilitate 'bring your own' Custom URL configurations.

• Source: ⚠️ https://gist.github.com/YLChen-007/fb1096bc8428bed9a428f764d9d103bb
• User: Eric-f (UID 96873)
• Submission: 04/23/2026 14:47 (3 months ago)
• Moderation: 05/17/2026 11:28 (24 days later)
• Status: Accepted
• VulDB entry: 364394 [vercel ai up to 3.0.97 provider-utils response-handler.ts resource consumption]
• Points: 20