# CVE-2026-93363: Payload CMS storage-vercel-blob access control bypass in uploads

Source: https://junglewise.ai/threats/cve-2026-93363-the-payloadcms-storage-vercel-blob-storage-adapter-for-payload  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-09-25. Updated: 2026-09-26  
License: CC BY 4.0 with a link back

CVE-2026-93363 · Severity: medium · CVSS 4.3 · Published 2026-09-25

Payload CMS is a headless content management system that manages digital content and media assets. The Vercel Blob storage adapter contains a flaw that allows authenticated users to upload files without the proper collection-level permissions, bypassing intended access controls. An attacker with any authenticated account could upload unauthorized files or overwrite existing content.

Vendors: [npm](https://junglewise.ai/threats/vendors/npm), [Payload](https://junglewise.ai/threats/vendors/payload).

## Quick answers

**Is CVE-2026-93363 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-93363 being exploited in the wild.

**How severe is CVE-2026-93363?** Medium severity, with a CVSS score of 4.3, published 25 September 2026.

**Which products and versions are affected?** @payloadcms/storage-vercel-blob (npm) >= 3.25.0, < 3.90.0, SEMVER:introduced=3.25.0,fixed=3.90.0; Payload Storage-Vercel-Blob >=3.25.0, <3.90.0; >=4.0.0-canary.0, <4.0.0-canary.34.

**Is there a fix for CVE-2026-93363?** Yes. @payloadcms/storage-vercel-blob (npm): upgrade to 3.90.0 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-93363 attacked?** It is attacked over the network, in a software library.

**Am I affected by CVE-2026-93363?** Check whether you run @payloadcms/storage-vercel-blob (npm) or Payload Storage-Vercel-Blob 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

- @payloadcms/storage-vercel-blob (npm): upgrade to 3.90.0 or later

  ```sh
  npm install @payloadcms/storage-vercel-blob@3.90.0
  ```


## Technical details

The @payloadcms/storage-vercel-blob adapter fails to enforce collection-level access controls on the client-upload route, allowing authenticated users to bypass intended authorization checks (CWE-862: Missing Authorization). An authenticated attacker can directly access the client-upload endpoint and upload files without possessing the required collection permissions. A fix is available in versions 3.90.0 or later and 4.0.0-canary.34 or later.

## Affected products

- Payload storage-vercel-blob >=3.25.0, <3.90.0; >=4.0.0-canary.0, <4.0.0-canary.34

## Identifiers

- CVE-2026-93363
- GHSA-mc8m-rr6c-r5qr

## Timeline

- 2026-09-25: disclosed

## References

- [https://github.com/payloadcms/payload/security/advisories/GHSA-mc8m-rr6c-r5qr](https://github.com/payloadcms/payload/security/advisories/GHSA-mc8m-rr6c-r5qr)
- [https://www.vulncheck.com/advisories/payload-cms-storage-vercel-blob-adapter-improper-access-control-on-upload-route](https://www.vulncheck.com/advisories/payload-cms-storage-vercel-blob-adapter-improper-access-control-on-upload-route)