5.3
MEDIUM CVSS 4.0
CVE-2026-93363
Payload CMS storage-vercel-blob Adapter Improper Access Control on Upload Route
Description

The @payloadcms/storage-vercel-blob storage adapter for Payload contains an improper access control vulnerability that allows authenticated users to bypass collection-level permissions by accessing the client-upload route directly. Attackers can upload files through the client-upload endpoint without possessing the required collection access permissions, circumventing the intended access control enforcement.

INFO

Published Date :

Sept. 25, 2026, 5:17 p.m.

Last Modified :

Sept. 25, 2026, 6:17 p.m.

Remotely Exploit :

Yes !
Affected Products

The following products are affected by CVE-2026-93363 vulnerability. Even if cvefeed.io is aware of the exact versions of the products that are affected, the information is not represented in the table below.

ID Vendor Product Action
1 Payloadcms payload
CVSS Scores
The Common Vulnerability Scoring System is a standardized framework for assessing the severity of vulnerabilities in software and systems. We collect and displays CVSS scores from various sources for each CVE.
Score Version Severity Vector Exploitability Score Impact Score Source
CVSS 134c704f-9b21-4f2e-91b3-4a467353bcc0
CVSS 3.1 MEDIUM 83251b91-4cc7-4094-a5c7-464a1b83ea10
CVSS 3.1 MEDIUM [email protected]
CVSS 4.0 MEDIUM 83251b91-4cc7-4094-a5c7-464a1b83ea10
CVSS 4.0 MEDIUM [email protected]
Solution
Restrict access to the client-upload endpoint to authorized users only.
  • Update the storage adapter to the latest version.
  • Review and enforce collection-level permissions.
  • Validate user authentication and authorization for file uploads.
References to Advisories, Solutions, and Tools

Here, you will find a curated list of external links that provide in-depth information, practical solutions, and valuable tools related to CVE-2026-93363.

URL Resource
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
CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorizes the common flaws or weaknesses that can lead to vulnerabilities. CVE-2026-93363 is associated with the following CWEs:

Common Attack Pattern Enumeration and Classification (CAPEC)

Common Attack Pattern Enumeration and Classification (CAPEC) stores attack patterns, which are descriptions of the common attributes and approaches employed by adversaries to exploit the CVE-2026-93363 weaknesses.

We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).

Results are limited to the first 15 repositories due to potential performance issues.

The following list is the news that have been mention CVE-2026-93363 vulnerability anywhere in the article.

The following table lists the changes that have been made to the CVE-2026-93363 vulnerability over time.

Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.

  • CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0

    Sep. 25, 2026

    Action Type Old Value New Value
    Added SSVC {'id': 'CVE-2026-93363', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'none'}, {'automatable': 'no'}, {'technicalImpact': 'partial'}], 'version': '2.0.3', 'timestamp': '2026-09-25T17:06:56.287708Z'}
  • New CVE Received by [email protected]

    Sep. 25, 2026

    Action Type Old Value New Value
    Added Description The @payloadcms/storage-vercel-blob storage adapter for Payload contains an improper access control vulnerability that allows authenticated users to bypass collection-level permissions by accessing the client-upload route directly. Attackers can upload files through the client-upload endpoint without possessing the required collection access permissions, circumventing the intended access control enforcement.
    Added CVSS V4.0 AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
    Added CVSS V3.1 AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N
    Added CWE CWE-862
    Added Affected New affected value received. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/93xxx/CVE-2026-93363.json">CVE-2026-93363</a>
    Added Reference https://github.com/payloadcms/payload/security/advisories/GHSA-mc8m-rr6c-r5qr
    Added Reference https://www.vulncheck.com/advisories/payload-cms-storage-vercel-blob-adapter-improper-access-control-on-upload-route
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days. Following chart shows the EPSS score history of the vulnerability.