CVE-2026-55096

Name of the Vulnerable Software and Affected Versions fast-mcp-telegram versions prior to 30.1

Description The server is subject to a full-read, exfiltrating Server-Side Request Forgery (SSRF), a condition where an attacker can force the server to make requests to internal resources. The send message and send message to phone MCP tools accept files as a list of http(s) URLs, which the server downloads and attaches to outgoing messages. While the validate url security function implements a denylist to check the literal hostname string, it does not resolve DNS. Since the actual fetch performed by httpx.AsyncClient.get resolves DNS at request time, a hostname resolving to a loopback, private, or link-local address can bypass the security guard. This allows an attacker to retrieve the body of the internal request as a Telegram file attachment, even when block private ips=True and allow http urls=False are configured.

Recommendations Update to version 30.1.