BREW-MCP-ATLASSIAN-GHSA-… (GHSA-489G-7RXV-6C8Q)
Vulnerability from osv_homebrew – Published: 2026-08-13 17:13 – Updated: 2026-10-05 19:48 – Source websiteMCP Atlassian is a Model Context Protocol (MCP) server for Atlassian products (Confluence and Jira). From 0.17.0 until 0.22.0, validate_url_for_ssrf resolves the attacker-controlled X-Atlassian-Jira-Url and X-Atlassian-Confluence-Url header host once at middleware time, but the outbound request is built with the raw hostname and resolves it again at connection time with no IP pinning. An attacker-controlled DNS-rebinding name can return a public IP during validation and 169.254.169.254 or another internal IP during connection, enabling unauthenticated server-side requests to cloud metadata or internal services. The flaw spans src/mcp_atlassian/utils/urls.py, src/mcp_atlassian/servers/main.py, and src/mcp_atlassian/servers/dependencies.py; validate_url_for_ssrf returns only a verdict rather than a pinned IP, UserTokenMiddleware processes the attacker-controlled headers before fetcher creation, and the Jira and Confluence fetchers use the raw hostname. This issue is fixed in version 0.22.0.
{
"affected": [
{
"ecosystem_specific": {
"fix": "bump",
"range_state": "fixed",
"upstream_fixed_in": "0.22.0"
},
"package": {
"ecosystem": "Homebrew",
"name": "mcp-atlassian",
"purl": "pkg:brew/mcp-atlassian"
},
"ranges": [
{
"events": [
{
"introduced": "0.11.9"
},
{
"fixed": "0.22.0"
}
],
"type": "ECOSYSTEM"
}
]
}
],
"database_specific": {
"confidence": "high",
"source": "matched",
"strategy": "git",
"upstream_evidence": [
{
"ecosystem": "GIT",
"key": "https://github.com/sooperset/mcp-atlassian",
"name": "https://github.com/sooperset/mcp-atlassian",
"strategy": "git",
"subject_version": "0.23.1"
},
{
"ecosystem": "PyPI",
"key": "pkg:pypi/mcp-atlassian@0.23.1",
"name": "mcp-atlassian",
"strategy": "registry",
"subject_version": "0.23.1"
}
]
},
"details": "MCP Atlassian is a Model Context Protocol (MCP) server for Atlassian products (Confluence and Jira). From 0.17.0 until 0.22.0, validate_url_for_ssrf resolves the attacker-controlled X-Atlassian-Jira-Url and X-Atlassian-Confluence-Url header host once at middleware time, but the outbound request is built with the raw hostname and resolves it again at connection time with no IP pinning. An attacker-controlled DNS-rebinding name can return a public IP during validation and 169.254.169.254 or another internal IP during connection, enabling unauthenticated server-side requests to cloud metadata or internal services. The flaw spans src/mcp_atlassian/utils/urls.py, src/mcp_atlassian/servers/main.py, and src/mcp_atlassian/servers/dependencies.py; validate_url_for_ssrf returns only a verdict rather than a pinned IP, UserTokenMiddleware processes the attacker-controlled headers before fetcher creation, and the Jira and Confluence fetchers use the raw hostname. This issue is fixed in version 0.22.0.",
"id": "BREW-mcp-atlassian-GHSA-489g-7rxv-6c8q",
"modified": "2026-10-05T19:48:04Z",
"published": "2026-08-13T17:13:13Z",
"references": [
{
"type": "WEB",
"url": "https://github.com/sooperset/mcp-atlassian/releases/tag/v0.22.0"
},
{
"type": "ADVISORY",
"url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/73xxx/CVE-2026-73497.json"
},
{
"type": "ADVISORY",
"url": "https://github.com/sooperset/mcp-atlassian/security/advisories/GHSA-489g-7rxv-6c8q"
},
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2026-73497"
},
{
"type": "FIX",
"url": "https://github.com/sooperset/mcp-atlassian/commit/b041733473f95119dd539542a43c280737a8e460"
},
{
"type": "FIX",
"url": "https://github.com/sooperset/mcp-atlassian/pull/1448"
}
],
"schema_version": "1.7.3",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:L/A:N",
"type": "CVSS_V3"
}
],
"summary": "MCP Atlassian is a Model Context Protocol (MCP): DNS-rebinding TOCTOU bypass of the SSRF fix (CVE-2026-27826): unauthenticated SSRF to cloud metadata",
"upstream": [
"GHSA-489g-7rxv-6c8q",
"CVE-2026-73497"
]
}
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