CVE-2026-33687
Sharp has Unrestricted File Upload via Client-Controlled Validation Rules
Impact
Sharp is a content management framework built for Laravel as a package. Versions prior to 9.20.0 contain a vulnerability in the file upload endpoint that allows authenticated users to bypass all file type restrictions. The upload endpoint within the `ApiFormUploadController` accepts a client-controlled `validation_rule` parameter. This parameter is directly passed into the Laravel validator without sufficient server-side enforcement. By intercepting the request and sending `validation_rule[]=file`, an attacker can completely bypass all MIME type and file extension restrictions. This issue has been addressed in version 9.20.0 by removing the client-controlled validation rules and strictly defining upload rules server-side. As a workaround, ensure that the storage disk used for Sharp uploads is strictly private. Under default configurations, an attacker cannot directly execute uploaded PHP files unless a public disk configuration is explicitly used.
Affected packages
| Ecosystem | Package | Affected | Fixed in |
|---|---|---|---|
| composer | code16/sharp | < 9.20.0 | 9.20.0 |
Affected products
| Vendor | Product | Affected versions |
|---|---|---|
| Code16 | Sharp | before 9.20.0 |
Weakness classification
References
- NVD record
- CVE.org record
- GitHub advisory
- https://github.com/advisories/GHSA-fr76-5637-w3g9
- https://github.com/code16/sharp/security/advisories/GHSA-fr76-5637-w3g9
- https://github.com/code16/sharp/pull/714
- https://github.com/code16/sharp/releases/tag/v9.20.0
- https://laravel.com/docs/13.x/filesystem
- https://nvd.nist.gov/vuln/detail/CVE-2026-33687