{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-77246", "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa", "state": "PUBLISHED", "assignerShortName": "GitHub_M", "dateReserved": "2026-08-20T19:02:23.416Z", "datePublished": "2026-09-22T18:51:54.540Z", "dateUpdated": "2026-09-24T15:26:33.550Z" }, "containers": { "cna": { "title": "MCP Atlassian: MCP HTTP Client Server-Local File Exfiltration via Unvalidated Attachment Upload Path", "problemTypes": [ { "descriptions": [ { "cweId": "CWE-22", "lang": "en", "description": "CWE-22: Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')", "type": "CWE" } ] }, { "descriptions": [ { "cweId": "CWE-200", "lang": "en", "description": "CWE-200: Exposure of Sensitive Information to an Unauthorized Actor", "type": "CWE" } ] }, { "descriptions": [ { "cweId": "CWE-441", "lang": "en", "description": "CWE-441: Unintended Proxy or Intermediary ('Confused Deputy')", "type": "CWE" } ] } ], "metrics": [ { "cvssV3_1": { "attackComplexity": "LOW", "attackVector": "ADJACENT_NETWORK", "availabilityImpact": "NONE", "baseScore": 7.4, "baseSeverity": "HIGH", "confidentialityImpact": "HIGH", "integrityImpact": "NONE", "privilegesRequired": "NONE", "scope": "CHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:C/C:H/I:N/A:N", "version": "3.1" } } ], "references": [ { "name": "https://github.com/sooperset/mcp-atlassian/security/advisories/GHSA-wv8v-v4c5-v75j", "tags": [ "x_refsource_CONFIRM" ], "url": "https://github.com/sooperset/mcp-atlassian/security/advisories/GHSA-wv8v-v4c5-v75j" }, { "name": "https://github.com/sooperset/mcp-atlassian/pull/1448", "tags": [ "x_refsource_MISC" ], "url": "https://github.com/sooperset/mcp-atlassian/pull/1448" }, { "name": "https://github.com/sooperset/mcp-atlassian/commit/b041733473f95119dd539542a43c280737a8e460", "tags": [ "x_refsource_MISC" ], "url": "https://github.com/sooperset/mcp-atlassian/commit/b041733473f95119dd539542a43c280737a8e460" }, { "name": "https://github.com/sooperset/mcp-atlassian/releases/tag/v0.22.0", "tags": [ "x_refsource_MISC" ], "url": "https://github.com/sooperset/mcp-atlassian/releases/tag/v0.22.0" } ], "affected": [ { "vendor": "sooperset", "product": "mcp-atlassian", "versions": [ { "version": "< 0.22.0", "status": "affected" } ] } ], "providerMetadata": { "orgId": "a0819718-46f1-4df5-94e2-005712e83aaa", "shortName": "GitHub_M", "dateUpdated": "2026-09-22T18:51:54.540Z" }, "descriptions": [ { "lang": "en", "value": "MCP Atlassian is a Model Context Protocol (MCP) server for Atlassian products (Confluence and Jira). Prior to 0.22.0, an HTTP transport deployment with READ_ONLY_MODE=false accepts a request without an Authorization identity and permits attacker-controlled Atlassian service headers, including X-Atlassian-Confluence-Url, to select a public attacker hostname or one allowed by MCP_ALLOWED_URL_DOMAINS. A caller can then invoke confluence_upload_attachment or the Jira attachment variant in src/mcp_atlassian/jira/attachments.py with a server-local file_path and cause the MCP process to send the file to the selected attachment endpoint. This issue is fixed in version 0.22.0." } ], "source": { "advisory": "GHSA-wv8v-v4c5-v75j", "discovery": "UNKNOWN" } }, "adp": [ { "references": [ { "url": "https://github.com/sooperset/mcp-atlassian/security/advisories/GHSA-wv8v-v4c5-v75j", "tags": [ "exploit" ] } ], "metrics": [ { "other": { "type": "ssvc", "content": { "timestamp": "2026-09-24T15:26:25.494462Z", "id": "CVE-2026-77246", "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": "2026-09-24T15:26:33.550Z" } } ] } }