FastMCP vulnerable to reflected XSS in client's callback page (jlowin fastmcp)
En bref
- Source
- NVD
- EPSS
- EPSS 0.28 % · centile 20 ()
- État
- PUBLISHED
- Publiée
- Mise à jour
- Attribuée par
- GitHub_M
- Statut NVD
- Analyzed
Description
FastMCP is the standard framework for building MCP applications. Versions prior to 2.13.0 have a reflected cross-site scripting vulnerability in the OAuth client callback page (oauth_callback.py) where unescaped user-controlled values are inserted into the generated HTML, allowing arbitrary JavaScript execution in the callback server origin. The issue is fixed in version 2.13.0.
Faiblesses (CWE)
- CWE-79 — Injection de code indirecte (XSS)
Références
Scores
| Version | Score | Vecteur | Évalué par |
|---|---|---|---|
| CVSS 4.0 | MEDIUM 5.3 | CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N | GitHub_M |
| CVSS 4.0 | MEDIUM 5.3 | CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X | NVD · security-advisories@github.com (Secondary) |
| CVSS 3.1 | MEDIUM 6.1 | CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N | NVD · nvd@nist.gov (Primary) |
Avis
- GHSA-mxxr-jv3v-6pgc — FastMCP vulnerable to reflected XSS in client's callback page
- PYSEC-2026-1364 — FastMCP vulnerable to reflected XSS in client's callback page
Références européennes
- ENISA EUVD · EUVD-2025-36568
- GCVE · GCVE-0-2025-62800
Configurations affectées (CPE NVD)
cpe:2.3:a:jlowin:fastmcp:*:*:*:*:*:*:*:*< 2.13.0
Produits affectés
| Produit | Versions |
|---|---|
| jlowin · fastmcp | affected < 2.13.0 |
Sources
| Source | Licence |
|---|---|
| CVE List (CVEProject cvelistV5) | CVE Program Terms of Use |
| EPSS (FIRST.org) | FIRST — attribution requested |
| ENISA EUVD | ENISA — reproduction authorised, source acknowledged |
| NVD (NIST) via fkie-cad/nvd-json-data-feeds | Public domain — this product uses data from the NVD API but is not endorsed or certified by the NVD |