{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-77255","assignerOrgId":"a0819718-46f1-4df5-94e2-005712e83aaa","state":"PUBLISHED","assignerShortName":"GitHub_M","dateReserved":"2026-08-20T19:02:23.417Z","datePublished":"2026-09-22T18:29:20.167Z","dateUpdated":"2026-09-26T00:00:47.513Z"},"containers":{"cna":{"title":"MCP Atlassian: Arbitrary File Read & Exfiltration (Confused Deputy) in JIRA update_issue","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-441","lang":"en","description":"CWE-441: Unintended Proxy or Intermediary ('Confused Deputy')","type":"CWE"}]}],"metrics":[{"cvssV3_1":{"attackComplexity":"LOW","attackVector":"NETWORK","availabilityImpact":"NONE","baseScore":8.6,"baseSeverity":"HIGH","confidentialityImpact":"HIGH","integrityImpact":"NONE","privilegesRequired":"NONE","scope":"CHANGED","userInteraction":"NONE","vectorString":"CVSS:3.1/AV:N/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-2xj6-xx86-cwwc","tags":["x_refsource_CONFIRM"],"url":"https://github.com/sooperset/mcp-atlassian/security/advisories/GHSA-2xj6-xx86-cwwc"},{"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":"2026-09-22T18:29:20.167Z"},"descriptions":[{"lang":"en","value":"MCP Atlassian is a Model Context Protocol (MCP) server for Atlassian products (Confluence and Jira). Prior to 0.22.0, the Jira update_issue attachments argument is converted into local paths and routed to the attachment upload implementation without workspace validation. A caller can make the MCP server read arbitrary local files and attach them to a Jira issue, using the server as a confused deputy to exfiltrate the contents. The advisory traces the vulnerable input and processing flow through jira update_issue, attachments, upload_attachment, and file_path, which identify the affected entry points, controls, and code paths. This issue is fixed in version 0.22.0."}],"source":{"advisory":"GHSA-2xj6-xx86-cwwc","discovery":"UNKNOWN"}},"adp":[{"references":[{"url":"https://github.com/sooperset/mcp-atlassian/security/advisories/GHSA-2xj6-xx86-cwwc","tags":["exploit"]}],"metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-09-26T00:00:16.341441Z","id":"CVE-2026-77255","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":"2026-09-26T00:00:47.513Z"}}]}}