What is CVE-2026-52830?

CVE-2026-52830 is a critical-severity vulnerability in Leshchenko1979 Fast-mcp-telegram, classified under Path Traversal. CVSS score: 9.4/10. Published 2026-07-02.

How severe is CVE-2026-52830?

Critical severity. CVSS v3 base score is 9.4 out of 10.

Auth bypass in Leshchenko1979 Fast-mcp-telegram

CVE-2026-52830

fast-mcp-telegram is a Telegram MCP Server. Prior to 0.19.1, fast-mcp-telegram validates HTTP Bearer tokens by joining the raw token string into a session-file path. The verifier rejects the exact reserved token telegram, but it does not r…

Vulnerability class: Path Traversal (Directory Traversal)

CVSS v3 metric

CVSS v3 base score 9.4 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:L.

Affected products

Leshchenko1979 Fast-mcp-telegram — versions < 0.19.1

Weakness classification (CWE)

CWE-22 — Path Traversal
CWE-287 — Improper Authentication

References

security-advisories@github.com (x_refsource_MISC)
security-advisories@github.com (x_refsource_CONFIRM)

Frequently asked questions

What is CVE-2026-52830?: CVE-2026-52830 is a critical-severity vulnerability in Leshchenko1979 Fast-mcp-telegram, classified under Path Traversal. CVSS score: 9.4/10. Published 2026-07-02.
How severe is CVE-2026-52830?: Critical severity. CVSS v3 base score is 9.4 out of 10.