Vulnerability in Mcp-Atlassian Mcp Atlassian

CVE-2026-77247

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.

Published · last modified .

CVSS v3 metric

CVSS v3 base score 6.5 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N.

EPSS exploit prediction

EPSS: 0.004 (33.0th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 33rd percentile — 33.0% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2026-77247: held from 0.004 to 0.004.

EPSS over last 30 days · oldest: 0.004 · newest: 0.004 · change: 0.000

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-77247?
CVE-2026-77247 is a medium-severity vulnerability in Mcp-Atlassian Mcp Atlassian, classified under External Control of File Name or Path. CVSS score: 6.5/10. Published 2026-09-22.
How severe is CVE-2026-77247?
Medium severity. CVSS v3 base score is 6.5 out of 10.