{"id":"CVE-2026-77246","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, an HTTP transport deployment with READ_ONLY_MODE=false accepts a request without an Authorization identity and permits …","severity":"high","cvss":7.4,"cvssVector":"CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:C/C:H/I:N/A:N","cwe":["CWE-22","CWE-200","CWE-441"],"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":"2026-09-28T14:31:10.220","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-77246","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-wv8v-v4c5-v75j","label":"security-advisories@github.com"},{"url":"https://github.com/sooperset/mcp-atlassian/security/advisories/GHSA-wv8v-v4c5-v75j","label":"134c704f-9b21-4f2e-91b3-4a467353bcc0"},{"url":"https://github.com/advisories/GHSA-wv8v-v4c5-v75j"},{"url":"https://github.com/sooperset/mcp-atlassian"},{"url":"https://pypi.org/project/mcp-atlassian"},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-77246"}],"tags":["nvd","cve.org","ghsa","pip","osv","exploit-available"],"epss":0.00471,"epssPercentile":0.40549,"aliases":["GHSA-wv8v-v4c5-v75j","PYSEC-2026-4104"],"ecosystem":"pip","exploitAvailable":true,"ssvc":{"exploitation":"poc","automatable":"no","technicalImpact":"partial","timestamp":"2026-09-24T15:26:25.494462Z"},"ingestedAt":"2026-09-22T19:09:09.999Z","slug":"CVE-2026-77246","body":"## Overview\n\nMCP 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.\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-2026-77246)\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-wv8v-v4c5-v75j","depth":"midnight","depthScore":53,"depthScoreParts":{"impact":40.7,"likelihood":0.1,"exploitation":12,"ransomware":0},"changes":[{"seq":210211,"id":"CVE-2026-77246","ts":1790264814326,"field":"exploit_available","old":"false","new":"true"}]}