Vulnerability · Published Sep 22, 2026 · Assigned by GitHub_M
CVE-2026-77247MCP Atlassian: Arbitrary server-local file upload to Jira/Confluence attachments via unrestricted file_path parameters
High 8.3
In plain English
A high-severity security flaw in mcp-atlassian from sooperset. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.4% (higher than 33% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official description
MCP Atlassian is a Model Context Protocol (MCP) server for Atlassian products (Confluence and Jira). Prior to 0.22.0, Jira and Confluence upload tools interpret caller-controlled path arguments on the MCP server and open those files before sending them as attachments. In remote or multi-user deployments, a permitted client can disclose host files without shell or direct filesystem access. The advisory traces the vulnerable input and processing flow through AttachmentsMixin.upload_attachment, AttachmentsMixin.upload_attachments, file_path, file_paths, and jira update_issue, which identify the affected entry points, controls, and code paths. This issue is fixed in version 0.22.0.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| PyPI | mcp-atlassian | 0.22.0 | GHSA-f6pj-qv47-g96w |
| PyPI | mcp-atlassian | 0.22.0 | PYSEC-2026-4092 |
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| sooperset | mcp-atlassian | < 0.22.0 |
Weakness: CWE-73 · Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:N/VA:N/SC:H/SI:N/SA:N
References
- https://github.com/sooperset/mcp-atlassian/security/advisories/GHSA-f6pj-qv47-g96w x_refsource_CONFIRM
- https://github.com/sooperset/mcp-atlassian/pull/1448 x_refsource_MISC
- https://github.com/sooperset/mcp-atlassian/commit/b041733473f95119dd539542a43c280737a8e460 x_refsource_MISC
- https://github.com/sooperset/mcp-atlassian/releases/tag/v0.22.0 x_refsource_MISC