CVE-2026-77257

MCP Atlassian: HTTP upload tools accept arbitrary server-local file paths

State
Published
Severity
8.3 High
Published
Sep 22, 2026
Updated
Sep 23, 2026
Reserved
Aug 20, 2026

Read the record on cve.org

Description

MCP Atlassian is a Model Context Protocol (MCP) server for Atlassian products (Confluence and Jira). Prior to 0.22.0, HTTP-exposed Jira and Confluence upload tools pass a caller-provided file_path to local file operations without restricting it to the workspace. A remote MCP caller with tool access can cause the server to read sensitive local files and upload them as Atlassian attachments. The advisory traces the vulnerable input and processing flow through streamable-http, upload_attachment, and file_path, which identify the affected entry points, controls, and code paths. This issue is fixed in version 0.22.0.

Scores

CVSSScoreVectorSource
4.08.3 HighCVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:N/VA:N/SC:H/SI:N/SA:NGitHub_M

Weaknesses

  • CWE-22 Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')

Affected Products

ProductVersions
mcp-atlassiansooperset
  • < 0.22.0Affected

References

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