# CVE-2026-8769: Vercel AI SDK denial of service in provider-utils response handler

Source: https://junglewise.ai/threats/cve-2026-8769-vercel-ai-sdk-denial-of-service-in-provider-utils-response-handler  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-05-17. Updated: 2026-05-29  
License: CC BY 4.0 with a link back

CVE-2026-8769 · Severity: medium · CVSS 4.3 · Published 2026-05-17

Vercel AI SDK is a library used by developers to integrate various AI models into their applications. A vulnerability in its response handling component allows a malicious AI provider or a compromised server to send an infinite stream of data, causing the application to run out of memory and crash. This can lead to a complete service outage (Denial of Service), especially in multi-tenant environments where users can configure their own AI endpoints.

Vendors: [npm](https://junglewise.ai/threats/vendors/npm), [Vercel](https://junglewise.ai/threats/vendors/vercel).

## Quick answers

**Is CVE-2026-8769 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-8769 being exploited in the wild.

**How severe is CVE-2026-8769?** Medium severity, with a CVSS score of 4.3, published 17 May 2026.

**Which products and versions are affected?** @ai-sdk/provider-utils (npm) SEMVER:introduced=0,fixed=3.0.28.

**Is there a fix for CVE-2026-8769?** Yes. @ai-sdk/provider-utils (npm): upgrade to 3.0.28 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-8769 attacked?** It is attacked over the network, in a software library.

**Am I affected by CVE-2026-8769?** Check whether you run @ai-sdk/provider-utils (npm), Vercel AI SDK OpenAI Provider or Vercel AI SDK Provider Utils at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## How to fix

- @ai-sdk/provider-utils (npm): upgrade to 3.0.28 or later

  ```sh
  npm install @ai-sdk/provider-utils@3.0.28
  ```


## Technical details

The @ai-sdk/provider-utils package lacks response size limits in its `createJsonResponseHandler` and `createJsonErrorResponseHandler` functions within `packages/provider-utils/src/response-handler.ts`. These handlers use `await response.text()` to buffer the entire HTTP response body into memory without constraints. An attacker who can control the API endpoint (baseURL) used by the SDK—common in agent orchestration platforms—can return an infinite chunked response. This causes the Node.js process to exhaust the V8 heap memory, resulting in a fatal 'out of memory' error and process termination. While other parts of the SDK use `readResponseWithSizeLimit()`, this specific pathway remains unprotected.

## Affected products

- Vercel AI SDK (provider-utils) <= 3.0.97

## Identifiers

- CVE-2026-8769
- GHSA-866g-f22w-33x8

## Timeline

- 2026-04-04: other: Vulnerability details and PoC shared in a public Gist
- 2026-05-17: disclosed: CVE-2026-8769 published by VulDB
- 2026-05-18: advisory: GitHub Advisory GHSA-866g-f22w-33x8 published

## References

- [https://gist.github.com/YLChen-007/fb1096bc8428bed9a428f764d9d103bb](https://gist.github.com/YLChen-007/fb1096bc8428bed9a428f764d9d103bb)
- [https://vuldb.com/submit/811406](https://vuldb.com/submit/811406)
- [https://vuldb.com/vuln/364394](https://vuldb.com/vuln/364394)
- [https://vuldb.com/vuln/364394/cti](https://vuldb.com/vuln/364394/cti)

## Related threats

- [Vercel AI SSRF via HTTP redirect in provider-utils](https://junglewise.ai/threats/cve-2026-8768-vercel-ai-ssrf-via-http-redirect-in-provider-utils)