{"id":"CVE-2026-77274","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, validate_url_for_ssrf has a backslash authority confusion because it interprets the authority differently from the Requ…","severity":"high","cvss":8.2,"cvssVector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:N","cwe":["CWE-918"],"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":"2026-09-28T13:41:36.657","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-77274","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-hgcf-4mq8-5266","label":"security-advisories@github.com"},{"url":"https://github.com/sooperset/mcp-atlassian/security/advisories/GHSA-hgcf-4mq8-5266","label":"134c704f-9b21-4f2e-91b3-4a467353bcc0"},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-77274"},{"url":"https://github.com/advisories/GHSA-hgcf-4mq8-5266"},{"url":"https://github.com/sooperset/mcp-atlassian"},{"url":"https://pypi.org/project/mcp-atlassian"}],"tags":["nvd","cve.org","exploit-available","ghsa","pip","osv"],"epss":0.0033,"epssPercentile":0.26026,"aliases":["GHSA-hgcf-4mq8-5266","PYSEC-2026-4096"],"ecosystem":"pip","exploitAvailable":true,"ssvc":{"exploitation":"poc","automatable":"yes","technicalImpact":"partial","timestamp":"2026-09-22T18:31:53.866509Z"},"scores":{"nvd":8.2,"cna":8.8},"ingestedAt":"2026-09-22T18:08:12.497Z","slug":"CVE-2026-77274","body":"## Overview\n\nMCP Atlassian is a Model Context Protocol (MCP) server for Atlassian products (Confluence and Jira). Prior to 0.22.0, validate_url_for_ssrf has a backslash authority confusion because it interprets the authority differently from the Requests connection layer in the header-based Jira and Confluence URL authentication flow. A crafted URL can validate as an external hostname while the HTTP client connects to an internal host, permitting server-side requests to protected network resources. 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-2026-77274)\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-hgcf-4mq8-5266","depth":"midnight","depthScore":57,"depthScoreParts":{"impact":45.1,"likelihood":0.1,"exploitation":12,"ransomware":0},"changes":[{"seq":211934,"id":"CVE-2026-77274","ts":1790604774222,"field":"cvss","old":"8.8","new":"8.2"},{"seq":209322,"id":"CVE-2026-77274","ts":1790104202859,"field":"exploit_available","old":"false","new":"true"}]}