Fastschema up to 0.15.1 File Upload pkg/rclonefs/base.go pkg/rclonefs/base.go.PutMultipart cross site scripting

Summaryinfo

A vulnerability classified as problematic was found in Fastschema up to 0.15.1. This affects the function pkg/rclonefs/base.go.PutMultipart of the file pkg/rclonefs/base.go of the component File Upload. Such manipulation leads to cross site scripting. This vulnerability is uniquely identified as CVE-2026-72583. The attack can be launched remotely. No exploit exists.

Detailsinfo

A vulnerability was found in Fastschema up to 0.15.1. It has been rated as problematic. Affected by this issue is the function pkg/rclonefs/base.go.PutMultipart of the file pkg/rclonefs/base.go of the component File Upload. The manipulation with an unknown input leads to a cross site scripting vulnerability. Using CWE to declare the problem leads to CWE-79. The product does not neutralize or incorrectly neutralizes user-controllable input before it is placed in output that is used as a web page that is served to other users. Impacted is integrity. CVE summarizes:

A stored cross-site scripting (XSS) vulnerability in fastschema through v0.15.1 allows a low-privileged authenticated user to upload an SVG file containing malicious JavaScript by bypassing the MIME type allow-list check. The pkg/rclonefs/base.go PutMultipart function validates the Content-Type header supplied by the client rather than inspecting the actual file content, enabling an attacker to rename a file to .jpg while specifying image/svg+xml to bypass the filter and store a script-bearing SVG in the web root.

The advisory is available at github.com. This vulnerability is handled as CVE-2026-72583 since 08/10/2026. The exploitation is known to be easy. The attack may be launched remotely. Successful exploitation requires user interaction by the victim. Technical details are known, but there is no available exploit. This vulnerability is assigned to T1059.007 by the MITRE ATT&CK project.

There is no information about possible countermeasures known. It may be suggested to replace the affected object with an alternative product.

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Productinfo

Name

• Fastschema

Version

• 0.15.0
• 0.15.1

CPE 2.3info

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CPE 2.2info

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