fastschema - Stored Cross-Site Scripting via MIME Type Bypass in File Upload
Priority LOW 24CWE-79Published · Updated
Key facts
- Attack vector
- Network
- Privileges required
- Low
- User interaction
- Required
- Attack complexity
- Low
- Impact type
- Cross-site scripting
- Confidentiality · integrity · availability
- Low · Low · None
- Fix status
- No fix listed
Attack profile from CVSS 3.1 · CNA. Fix status from CNA. Impact type from CWE-79.
Summary
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.
Why it matters now
Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00255 17th percentileScored 2026-11-07
Fix No fix listed No fixed version in the sources yet
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- No
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| fastschema | fastschema | up to 0.15.1 | — | No fix listed | CNA |
- fastschema Vendorfastschema Affected up to 0.15.1 Fixed in — No fix listed CNA
Remediation
No fixed version listed by the sources yet.
Timeline
- 2026-10-02 Threatist record created from CVE-2026-72583
- 2026-10-03 Alias added: GHSA-6vrh-w6p3-v6fh
References
Advisory 1
Other 1
More fastschema vulnerabilities
- TI-2026-50840 fastschema - Unauthenticated NULL Pointer Dereference DoS in Account Recovery Endpoint CVSS 3.1HIGH 7.5
- TI-2026-50842 fastschema - TOCTOU Race Condition Bypasses OTP Attempt Limit in Account Recovery CVSS 3.1HIGH 7.4
Sources
- CVE-2026-72583 · CVE Program
- CVE-2026-72583 · NVD
- FIRST EPSS
- GHSA-6vrh-w6p3-v6fh · GitHub Advisory Database · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences