CVSS 3.1
8.6 highCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:N/A:NCVE-2026-77255
High (8.6) in mcp-atlassian mcp atlassian. EPSS 0.5% chance of exploitation in the next 30 days. Fixed in mcp-atlassian 0.22.0.
MCP Atlassian is a Model Context Protocol (MCP) server for Atlassian products (Confluence and Jira). Prior to 0.22.0, the Jira update_issue attachments argument is converted into local paths and routed to the attachment upload implementation without workspace validation. A caller can make the MCP server read arbitrary local files and attach them to a Jira issue, using the server as a confused deputy to exfiltrate the contents. The advisory traces the vulnerable input and processing flow through jira update_issue, attachments, upload_attachment, and file_path, which identify the affected entry points, controls, and code paths. This issue is fixed in version 0.22.0.
Severity
- EPSS
- 0.5% chance of exploitation in the next 30 days; higher than 39% of CVEs (scores of 2026-10-31)
- CWEs
- CWE-22, CWE-441
- Published
- Modified
- Record from
- the NVD, synced
Affected
- mcp-atlassian:mcp_atlassian
Packages (OSV)
| Advisory | Ecosystem | Package | Affected | Fixed in |
|---|---|---|---|---|
| GHSA-2xj6-xx86-cwwc | PyPI | mcp-atlassian | <0.22.0 | 0.22.0 |
| PYSEC-2026-4080 | PyPI | mcp-atlassian | <0.22.0 | 0.22.0 |
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-2xj6-xx86-cwwc
- https://github.com/sooperset/mcp-atlassian/security/advisories/GHSA-2xj6-xx86-cwwc