CVE-2026-22707 Strapi Upload Plugin MIME Validation Bypass via Content API
Authenticated users can bypass MIME restrictions to upload malicious files, leading to admin session hijacking and code execution.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-22707?
CVE-2026-22707 is a medium-severity vulnerability in @strapi/upload, published on 14 May 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Official description
Strapi is an open source headless content management system. In Strapi versions prior to 5.33.3, the Upload plugin's Content API endpoints did not enforce the administrator-configured MIME type restrictions (`plugin.upload.security.allowedTypes` and `deniedTypes`). The same restrictions were correctly enforced on the Admin Panel upload path. The upload plugin's `enforceUploadSecurity` security check was invoked in the admin upload controller but was missing from the Content API controller. The Content API handlers `uploadFiles` and `replaceFile` (and the `upload` wrapper that dispatches to them) called the underlying upload service directly, bypassing both the magic-byte MIME detection and the configured allow/deny lists. An authenticated user with the Content API upload permission could therefore upload file types the administrator had explicitly disallowed, including HTML and SVG content. In deployments serving uploaded files from the same origin as the admin panel (default), an attacker could upload an HTML or SVG file that, when opened directly by an admin, executed JavaScript in the admin origin, enabling admin-session hijack and authenticated administrative actions against the admin API. The patch in version 5.33.3 introduces a shared `prepareUploadRequest` helper that wraps `enforceUploadSecurity` and is called from both the Content API and admin upload controllers, ensuring identical security policy enforcement on every upload entry point.
Which versions are affected by CVE-2026-22707?
2 open source packages ship an affected version, including @strapi/upload. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
@strapi/upload npm | All versions | 5.33.3 |
@strapi/upload npm | All versions | 5.33.3 |
Products include Strapi Strapi.
How do I fix CVE-2026-22707?
Upgrade @strapi/upload to 5.33.3 or later.
Is CVE-2026-22707 being exploited?
There is no known exploitation of CVE-2026-22707 in the wild and no public exploit code.
Other vulnerabilities in @strapi/upload
- CVE-2023-22894 Strapi Cleartext Storage of Sensitive Information
- CVE-2023-22621 Strapi plugins vulnerable to Server-Side Template Injection and Remote Code Execution in the Users-Permissions Plugin
- CVE-2022-27263 Unrestricted Upload of File with Dangerous Type in Strapi
- CVE-2020-27664 Authorization bypass in Strapi
- CVE-2019-18818 Strapi allows unauthenticated attacker to reset admin password without valid reset token
Sources
Also known as GHSA-pcw7-5633-82vv.