{"cve":"CVE-2026-77244","nvd":{"published":"2026-09-22T18:17:17.560","modified":"2026-09-29T15:17:49.490","status":"Analyzed","description":"MCP Atlassian is a Model Context Protocol (MCP) server for Atlassian products (Confluence and Jira). Prior to 0.22.0, the HTTP transport accepts requests without a verified user identity and downstream fetcher construction falls back to the operator's globally configured Jira or Confluence credentials. A network client that can reach the MCP endpoint can invoke Atlassian tools as the operator, including read and write operations available to that account. The advisory traces the vulnerable input and processing flow through UserTokenMiddleware, AtlassianOpaqueTokenVerifier, _get_fetcher, and streamable-http, which identify the affected entry points, controls, and code paths. This issue is fixed in version 0.22.0.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:N","score":10.0},"cwes":["CWE-287","CWE-303","CWE-862"],"references":["https://github.com/sooperset/mcp-atlassian/commit/b041733473f95119dd539542a43c280737a8e460","https://github.com/sooperset/mcp-atlassian/pull/1448","https://github.com/sooperset/mcp-atlassian/releases/tag/v0.22.0","https://github.com/sooperset/mcp-atlassian/security/advisories/GHSA-wrhw-j3f9-8vc6"],"products":["mcp-atlassian:mcp_atlassian"],"source":"nvd","synced_at":"2026-10-19T22:56:02.509636177+00:00"},"epss":{"cve":"CVE-2026-77244","score":0.00346,"percentile":0.28222,"date":"2026-10-31"},"kev":null,"osv":[{"id":"GHSA-wrhw-j3f9-8vc6","url":"https://osv.dev/vulnerability/GHSA-wrhw-j3f9-8vc6","summary":"[mcp-atlassian] Authentication bypass in HTTP transport: AtlassianOpaqueTokenVerifier accepts any non-empty token","modified":"2026-10-01T17:55:56.993518686Z","packages":[{"ecosystem":"PyPI","name":"mcp-atlassian","purl":"pkg:pypi/mcp-atlassian","ranges":["<0.22.0"],"fixed":["0.22.0"]}]},{"id":"PYSEC-2026-4103","url":"https://osv.dev/vulnerability/PYSEC-2026-4103","summary":"[mcp-atlassian] Authentication bypass in HTTP transport: AtlassianOpaqueTokenVerifier accepts any non-empty token","modified":"2026-10-01T17:45:11.749243966Z","packages":[{"ecosystem":"PyPI","name":"mcp-atlassian","purl":"pkg:pypi/mcp-atlassian","ranges":["<0.22.0"],"fixed":["0.22.0"]}]}],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}