{"id":"CVE-2026-77248","title":"MCP Atlassian is a Model Context Protocol (MCP) server for Atlassian products (Confluence and Jira)","summary":"MCP Atlassian is a Model Context Protocol (MCP) server for Atlassian products (Confluence and Jira). Prior to 0.22.0, the streamable HTTP transport accepts requests without a user identity and falls back to operator credentials, while up…","severity":"high","cvss":8.6,"cvssVector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:N/A:N","cwe":["CWE-22","CWE-306"],"vendor":"mcp-atlassian","product":"mcp_atlassian","affected":["mcp_atlassian < 0.22.0"],"patched":["mcp_atlassian 0.22.0"],"published":"2026-09-22","updated":"2026-09-28","sourceUpdated":"2026-09-28T13:33:54.863","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-77248","references":[{"url":"https://github.com/sooperset/mcp-atlassian/commit/b041733473f95119dd539542a43c280737a8e460","label":"security-advisories@github.com"},{"url":"https://github.com/sooperset/mcp-atlassian/pull/1448","label":"security-advisories@github.com"},{"url":"https://github.com/sooperset/mcp-atlassian/releases/tag/v0.22.0","label":"security-advisories@github.com"},{"url":"https://github.com/sooperset/mcp-atlassian/security/advisories/GHSA-cc5h-2pwp-pvcc","label":"security-advisories@github.com"},{"url":"https://github.com/sooperset/mcp-atlassian/security/advisories/GHSA-cc5h-2pwp-pvcc","label":"134c704f-9b21-4f2e-91b3-4a467353bcc0"},{"url":"https://github.com/advisories/GHSA-cc5h-2pwp-pvcc"},{"url":"https://github.com/sooperset/mcp-atlassian"},{"url":"https://pypi.org/project/mcp-atlassian"},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-77248"}],"tags":["nvd","cve.org","ghsa","pip","osv","exploit-available"],"epss":0.00475,"epssPercentile":0.40859,"aliases":["GHSA-cc5h-2pwp-pvcc","PYSEC-2026-4089"],"ecosystem":"pip","exploitAvailable":true,"ssvc":{"exploitation":"poc","automatable":"yes","technicalImpact":"partial","timestamp":"2026-09-24T15:23:22.839643Z"},"ingestedAt":"2026-09-22T19:09:10.002Z","slug":"CVE-2026-77248","body":"## Overview\n\nMCP Atlassian is a Model Context Protocol (MCP) server for Atlassian products (Confluence and Jira). Prior to 0.22.0, the streamable HTTP transport accepts requests without a user identity and falls back to operator credentials, while upload_attachment accepts an unrestricted file_path. An unauthenticated network caller can read files available to the MCP process, upload them to an attacker-selected Jira issue or Confluence page, and retrieve the contents. The advisory traces the vulnerable input and processing flow through streamable-http, UserTokenMiddleware, upload_attachment, file_path, and _get_fetcher, which identify the affected entry points, controls, and code paths. This issue is fixed in version 0.22.0.\n\n## Affected\n\n- `mcp_atlassian < 0.22.0`\n\n## Remediation\n\nUpgrade past the affected range:\n\n- `mcp_atlassian 0.22.0`\n\n## Package advisory (CVE-2026-77248)\n\nAffected packages:\n\n- `mcp-atlassian < 0.22.0`\n\nPatched in:\n\n- `mcp-atlassian 0.22.0`\n\nSource: https://github.com/advisories/GHSA-cc5h-2pwp-pvcc","depth":"midnight","depthScore":59,"depthScoreParts":{"impact":47.3,"likelihood":0.1,"exploitation":12,"ransomware":0},"changes":[{"seq":210213,"id":"CVE-2026-77248","ts":1790264814408,"field":"exploit_available","old":"false","new":"true"}]}