CVE-2025-62800EPSS p18.5%

CVE-2025-62800CVE-2025-62800

jlowin / fastmcp

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.

Scoring

CVSS 6.1 ()
VectorCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
EPSS0.28% probability of exploitation · percentile 18.5% · 2026-10-10T12:00:23Z
Last modified2026-10-08
Sourced from NVD + FIRST.org EPSS. Curated for EU compliance use cases by Adam Lundqvist, Founder at SQUR.