CVE-2026-77266

Medium

Description

MCP Atlassian is a Model Context Protocol (MCP) server for Atlassian products (Confluence and Jira). Prior to 0.22.0, upload_attachment accepts absolute paths and traversal sequences without constraining the resolved path to the server workspace. An MCP caller with attachment access can read a chosen server-local file and exfiltrate it through Jira or Confluence. The advisory traces the vulnerable input and processing flow through upload_attachment, file_path, and path traversal, which identify the affected entry points, controls, and code paths. This issue is fixed in version 0.22.0.

SeverityMedium

CVSS6.5

Exploit probability—

ProductMcp-atlassian Mcp Atlassian

PublishedSep 22, 2026

First seenSep 22, 2026

Weakness typeCWE-22Path traversal

How to fix

Update

mcp-atlassian mcp_atlassian0.22.0 or later
mcp-atlassian0.22.0 or later

Affected products

Product	Affected versions	Fixed in
mcp-atlassian mcp_atlassian	v < 0.22.0	0.22.0
mcp-atlassianPyPI	v < 0.22.0	0.22.0

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