high8.3
CVE-2026-77267
MCP Atlassian is a Model Context Protocol (MCP) server for Atlassian products (Confluence and Jira).
Impact
MCP Atlassian is a Model Context Protocol (MCP) server for Atlassian products (Confluence and Jira). Prior to 0.22.0, the X-Atlassian-Jira-Url and X-Atlassian-Confluence-Url headers are processed by _process_authentication_headers and used to construct Atlassian fetchers without calling validate_url_for_ssrf. A caller who can set these headers can supply an internal or metadata-service URL and cause the server to send requests to that destination, bypassing the incomplete CVE-2026-27826 remediation. This issue is fixed in version 0.22.0.
Affected packages
| Ecosystem | Package | Affected | Fixed in |
|---|---|---|---|
| pip | mcp-atlassian | < 0.22.0 | 0.22.0 |
Affected products
| Vendor | Product | Affected versions |
|---|---|---|
| Mcp-Atlassian | Mcp Atlassian | before 0.22.0 |
Weakness classification
References
- NVD record
- CVE.org record
- GitHub advisory
- https://github.com/advisories/GHSA-5wf4-jqxh-8gm3
- https://github.com/sooperset/mcp-atlassian/security/advisories/GHSA-5wf4-jqxh-8gm3
- https://nvd.nist.gov/vuln/detail/CVE-2026-77267
- https://github.com/sooperset/mcp-atlassian/pull/1448
- https://github.com/sooperset/mcp-atlassian/commit/b041733473f95119dd539542a43c280737a8e460
- https://github.com/sooperset/mcp-atlassian/releases/tag/v0.22.0