CVE-2026-72583

fastschema - Stored Cross-Site Scripting via MIME Type Bypass in File Upload

Published Aug 10, 2026 CVSS 3.1 · 5.4 Medium EPSS < 1% KEV · Not listed
Description
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.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

No advisories available
History
Type Values Removed Values Added
First Time appeared Fastschema
Fastschema fastschema
Vendors & Products Fastschema
Fastschema fastschema
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Type Values Removed Values Added
Description 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. 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.
Type Values Removed Values Added
Description 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.
Title fastschema - Stored Cross-Site Scripting via MIME Type Bypass in File Upload
Weaknesses CWE-79
References
Metrics cvssV3_1

{'score': 5.4, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
TuranSec
Published
Updated
Aug 10, 2026, 1:18 PM
Reserved
Aug 10, 2026, 10:32 AM
Status
Deferred
Published
Aug 10, 2026, 11:17 AM
Modified
Oct 24, 2026, 3:10 PM