{"id":"CVE-2026-77246","published":"2026-09-22T19:16:48.730","lastModified":"2026-09-28T14:31:10.220","description":"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.","cvssScore":7.4,"cvssSeverity":"HIGH","cvssVector":"CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:C/C:H/I:N/A:N","cwes":["CWE-22","CWE-200","CWE-441"],"vendors":["mcp-atlassian"],"products":["mcp atlassian"],"references":[{"url":"https://github.com/sooperset/mcp-atlassian/commit/b041733473f95119dd539542a43c280737a8e460","tags":["Patch"]},{"url":"https://github.com/sooperset/mcp-atlassian/pull/1448","tags":["Issue Tracking","Patch"]},{"url":"https://github.com/sooperset/mcp-atlassian/releases/tag/v0.22.0","tags":["Release Notes"]},{"url":"https://github.com/sooperset/mcp-atlassian/security/advisories/GHSA-wv8v-v4c5-v75j","tags":["Exploit","Vendor Advisory"]},{"url":"https://github.com/sooperset/mcp-atlassian/security/advisories/GHSA-wv8v-v4c5-v75j","tags":["Exploit","Vendor Advisory"]}],"exploitRefs":[{"url":"https://github.com/sooperset/mcp-atlassian/commit/b041733473f95119dd539542a43c280737a8e460","tags":["Patch"]},{"url":"https://github.com/sooperset/mcp-atlassian/pull/1448","tags":["Issue Tracking","Patch"]},{"url":"https://github.com/sooperset/mcp-atlassian/releases/tag/v0.22.0","tags":["Release Notes"]},{"url":"https://github.com/sooperset/mcp-atlassian/security/advisories/GHSA-wv8v-v4c5-v75j","tags":["Exploit","Vendor Advisory"]},{"url":"https://github.com/sooperset/mcp-atlassian/security/advisories/GHSA-wv8v-v4c5-v75j","tags":["Exploit","Vendor Advisory"]}],"hasPoc":true,"ai":null}