{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-55096","assignerOrgId":"a0819718-46f1-4df5-94e2-005712e83aaa","state":"PUBLISHED","assignerShortName":"GitHub_M","dateReserved":"2026-06-16T14:41:54.578Z","datePublished":"2026-09-28T16:38:26.730Z","dateUpdated":"2026-10-01T14:39:11.027Z"},"containers":{"cna":{"title":"SSRF via DNS-resolution gap in _validate_url_security (file download by URL)","problemTypes":[{"descriptions":[{"cweId":"CWE-184","lang":"en","description":"CWE-184: Incomplete List of Disallowed Inputs","type":"CWE"}]},{"descriptions":[{"cweId":"CWE-918","lang":"en","description":"CWE-918: Server-Side Request Forgery (SSRF)","type":"CWE"}]}],"metrics":[{"cvssV3_1":{"attackComplexity":"LOW","attackVector":"NETWORK","availabilityImpact":"NONE","baseScore":7.1,"baseSeverity":"HIGH","confidentialityImpact":"HIGH","integrityImpact":"LOW","privilegesRequired":"LOW","scope":"UNCHANGED","userInteraction":"NONE","vectorString":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:L/A:N","version":"3.1"}}],"references":[{"name":"https://github.com/leshchenko1979/fast-mcp-telegram/security/advisories/GHSA-xr72-j7vj-vp7g","tags":["x_refsource_CONFIRM"],"url":"https://github.com/leshchenko1979/fast-mcp-telegram/security/advisories/GHSA-xr72-j7vj-vp7g"},{"name":"https://github.com/leshchenko1979/fast-mcp-telegram/commit/e6b3032cfc906e14f5b84f2c2b8ec378eb457e57","tags":["x_refsource_MISC"],"url":"https://github.com/leshchenko1979/fast-mcp-telegram/commit/e6b3032cfc906e14f5b84f2c2b8ec378eb457e57"},{"name":"https://github.com/leshchenko1979/fast-mcp-telegram/releases/tag/0.30.1","tags":["x_refsource_MISC"],"url":"https://github.com/leshchenko1979/fast-mcp-telegram/releases/tag/0.30.1"}],"affected":[{"vendor":"leshchenko1979","product":"fast-mcp-telegram","versions":[{"version":"< 30.1","status":"affected"}]}],"providerMetadata":{"orgId":"a0819718-46f1-4df5-94e2-005712e83aaa","shortName":"GitHub_M","dateUpdated":"2026-09-28T16:38:26.730Z"},"descriptions":[{"lang":"en","value":"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."}],"source":{"advisory":"GHSA-xr72-j7vj-vp7g","discovery":"UNKNOWN"}},"adp":[{"references":[{"url":"https://github.com/leshchenko1979/fast-mcp-telegram/security/advisories/GHSA-xr72-j7vj-vp7g","tags":["exploit"]}],"metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-10-01T14:38:52.830142Z","id":"CVE-2026-55096","options":[{"Exploitation":"poc"},{"Automatable":"no"},{"Technical Impact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"title":"CISA ADP Vulnrichment","providerMetadata":{"orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","shortName":"CISA-ADP","dateUpdated":"2026-10-01T14:39:11.027Z"}}]}}