CVE-2025-62800
- Source
- https://nvd.nist.gov/vuln/detail/CVE-2025-62800
- Import Source
- https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2025-62800.json
- JSON Data
- https://api.test.osv.dev/v1/vulns/CVE-2025-62800
- Aliases
- Published
- 2025-10-28T21:34:40.392Z
- Modified
- 2025-12-02T20:17:50.757877Z
- Severity
-
- 5.3 (Medium) CVSS_V4 - 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 CVSS Calculator
- Summary
- FastMCP vulnerable to reflected XSS in client's callback page
- Details
-
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.
- Database specific
{ "cna_assigner": "GitHub_M", "cwe_ids": [ "CWE-79" ], "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2025/62xxx/CVE-2025-62800.json" }- References
Affected packages
Git / github.com/jlowin/fastmcp
Affected ranges
- Type
- GIT
- Repo
- https://github.com/jlowin/fastmcp
- Events
-
Introduced0 Unknown introduced commit / All previous commits are affectedFixed
Affected versions
v0.*
v0.1.0
v0.2.0
v0.3.0
v0.3.1
v0.3.2
v0.3.3
v0.3.4
v0.3.5
v0.4.0
v0.4.1
v1.*
v1.0
v2.*
v2.0.0
v2.1.0
v2.1.1
v2.1.2
v2.10.0
v2.10.1
v2.10.2
v2.10.3
v2.10.4
v2.10.5
v2.10.6
v2.11.0
v2.11.1
v2.11.2
v2.11.3
v2.12.0
v2.12.0rc1
v2.12.1
v2.12.2
v2.12.3
v2.12.4
v2.13.0rc1
v2.13.0rc2
v2.13.0rc3
v2.2.0
v2.2.1
v2.2.10
v2.2.2
v2.2.3
v2.2.4
v2.2.5
v2.2.6
v2.2.7
v2.2.8
v2.2.9
v2.3.0
v2.3.0-rc.1
v2.3.0-rc.2
v2.3.1
v2.3.2
v2.3.3
v2.3.4
v2.3.5
v2.4.0
v2.5.0
v2.5.1
v2.5.2
v2.6.0
v2.6.1
v2.7.0
v2.7.1
v2.8.0
v2.8.1
v2.9.0
v2.9.1
v2.9.2