{"id":"CVE-2026-55096","title":"fast-mcp-telegram is a Telegram MCP Server","summary":"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. Downloa…","severity":"high","cvss":7.1,"cvssVector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:L/A:N","cwe":["CWE-184","CWE-918"],"vendor":"leshchenko1979","product":"fast-mcp-telegram","affected":["fast-mcp-telegram < 30.1"],"published":"2026-09-28","updated":"2026-10-01","sourceUpdated":"2026-10-01T15:17:30.070","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-55096","references":[{"url":"https://github.com/leshchenko1979/fast-mcp-telegram/commit/e6b3032cfc906e14f5b84f2c2b8ec378eb457e57","label":"security-advisories@github.com"},{"url":"https://github.com/leshchenko1979/fast-mcp-telegram/releases/tag/0.30.1","label":"security-advisories@github.com"},{"url":"https://github.com/leshchenko1979/fast-mcp-telegram/security/advisories/GHSA-xr72-j7vj-vp7g","label":"security-advisories@github.com"},{"url":"https://github.com/leshchenko1979/fast-mcp-telegram/security/advisories/GHSA-xr72-j7vj-vp7g","label":"134c704f-9b21-4f2e-91b3-4a467353bcc0"}],"tags":["nvd","cve.org","exploit-available"],"exploitAvailable":true,"ssvc":{"exploitation":"poc","automatable":"no","technicalImpact":"partial","timestamp":"2026-10-01T14:38:52.830142Z"},"epss":0.00254,"epssPercentile":0.1685,"ingestedAt":"2026-09-28T17:16:27.812Z","slug":"CVE-2026-55096","body":"## Overview\n\nfast-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.\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"midnight","depthScore":51,"depthScoreParts":{"impact":39.1,"likelihood":0.1,"exploitation":12,"ransomware":0},"changes":[{"seq":214333,"id":"CVE-2026-55096","ts":1790869738523,"field":"exploit_available","old":"false","new":"true"}]}