{"id":"CVE-2026-77254","published":"2026-09-22T19:16:49.693","lastModified":"2026-09-28T13:22:14.527","description":"MCP Atlassian is a Model Context Protocol (MCP) server for Atlassian products (Confluence and Jira). Prior to 0.22.0, requests to the HTTP MCP endpoint without a per-user identity are allowed to reach tool handlers, which then use globally configured Jira or Confluence credentials. A network caller can perform operations with the operator account's permissions unless the deployment has an independent authentication boundary. The advisory traces the vulnerable input and processing flow through streamable-http, UserTokenMiddleware, _get_fetcher, and global credentials, which identify the affected entry points, controls, and code paths. This issue is fixed in version 0.22.0.","cvssScore":9.1,"cvssSeverity":"CRITICAL","cvssVector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N","cwes":["CWE-306"],"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-vc8m-84rp-53hx","tags":["Exploit","Vendor Advisory"]},{"url":"https://github.com/sooperset/mcp-atlassian/security/advisories/GHSA-vc8m-84rp-53hx","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-vc8m-84rp-53hx","tags":["Exploit","Vendor Advisory"]},{"url":"https://github.com/sooperset/mcp-atlassian/security/advisories/GHSA-vc8m-84rp-53hx","tags":["Exploit","Vendor Advisory"]}],"hasPoc":true,"ai":{"summary":"The flaw allows network callers to perform operations with the operator account's permissions via the HTTP MCP endpoint without proper authentication, posing a critical risk.","exploitability":"Exploitation is relatively straightforward as it requires sending requests to the HTTP MCP endpoint without a per-user identity, which can be done by network callers.","blast_radius":"If exploited, this can lead to unauthorized access and operations with high privileges, impacting the security and integrity of the Atlassian products Confluence and Jira.","remediation":"Upgrade to version 0.22.0 or later.","detection":"No reliable host or network indicator is derivable from the published description.","tags":["auth-bypass","web","atlassian","mcp"],"model":"qwen2.5:7b-instruct","analyzedAt":"2026-09-28T08:51:24.983Z"}}