Vulnerability · Published Aug 10, 2026 · Assigned by TuranSec
CVE-2026-72583fastschema - Stored Cross-Site Scripting via MIME Type Bypass in File Upload
Medium 5.4
In plain English
A medium-severity cross-site scripting in fastschema from fastschema. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.3% (higher than 17% of all known vulnerabilities).
Severity (CVSS 3.1)5.4Medium
Exploit odds (30 days)0.3%top 82.8% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack toolingNoneno public tooling known
Official 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.
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| fastschema | fastschema | 0 – through 0.15.1 |
Weakness: CWE-79 · Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N
References
- Product third-party-advisory
- Vulnerable File technical-description