CVE-2026-55096

fast-mcp-telegram is a Telegram MCP Server. Prior to version 30.1, the send_message/send_message_to_phone MCP tools accept files as a list of http(s) URLs, which the server downloads and attaches to the outgoing Telegram message. Downloads are guarded by _validate_url_security, an SSRF denylist that checks the URL's literal hostname string but never resolves DNS. The fetch (httpx.AsyncClient.get) does its own resolution at request time. Consequently a hostname that resolves to a loopback / private / link-local address passes the guard and is fetched — even with the secure defaults block_private_ips=True and allow_http_urls=False. Because the fetched body is returned to the attacker as a Telegram file attachment, this is a full-read, exfiltrating SSRF, not blind. This issue has been patched in version 30.1.

• CWE-184
• CWE-918

• https://github.com/leshchenko1979/fast-mcp-telegram/commit/e6b3032cfc906e14f5b84f2c2b8ec378eb457e57
• https://github.com/leshchenko1979/fast-mcp-telegram/releases/tag/0.30.1
• https://github.com/leshchenko1979/fast-mcp-telegram/security/advisories/GHSA-xr72-j7vj-vp7g

Published

Sep 28, 2026

Last Modified

Sep 28, 2026

Status

Received

• One Click Account Takeover in GranolaHow a notification link broke out of Electron and led to a one-click account takeover.
• Autonomous PentestingAI agents that find and validate exploitable vulnerabilities like this one across your applications.
• PR ReviewsPentest every pull request so vulnerable code is caught before it ships to production.
• AI Penetration TestingHow AI-driven penetration testing continuously covers your attack surface.

• CVE-2026-5509An authenticated command injection vulnerability exists in t…7.2
• CVE-2026-55090Etherpad is a real-time collaborative editor. Prior to 3.3.0…5.3
• CVE-2026-55091flat-to-nested converts a hierarchy from a flat representati…7.5
• CVE-2026-55092Trivy is a security scanner. Prior to 0.71.1, when Trivy dow…7.5
• CVE-2026-55093Tract is a tiny, no-nonsense, self-contained TensorFlow and …6.1
• CVE-2026-55095OpenProject is open-source, web-based project management sof…5.3
• CVE-2026-55099icalendar is an RFC 5545 compatible parser and generator of …7.5
• CVE-2026-5510The GiveWP – Donation Plugin and Fundraising Platform plugin…6.4
• CVE-2026-55100hashi-vault-js is a Node.js module for interacting with the …8.7
• CVE-2026-55102hashi-vault-js is a Node.js module for interacting with the …5.8
• CVE-2026-55105Joplin is an open source note-taking and to-do application t…7.7
• CVE-2026-55106authentik is an open-source identity provider. Prior to 2026…5.3