CVE-2026-27825

Severity CVSS v4.0:

Pending analysis

Type:

CWE-22 Path Traversal

Publication date:

10/03/2026

Last modified:

02/04/2026

Description

MCP Atlassian is a Model Context Protocol (MCP) server for Atlassian products (Confluence and Jira). Prior to version 0.17.0, the `confluence_download_attachment` MCP tool accepts a `download_path` parameter that is written to without any directory boundary enforcement. An attacker who can call this tool and supply or access a Confluence attachment with malicious content can write arbitrary content to any path the server process has write access to. Because the attacker controls both the write destination and the written content (via an uploaded Confluence attachment), this constitutes for arbitrary code execution (for example, writing a valid cron entry to `/etc/cron.d/` achieves code execution within one scheduler cycle with no server restart required). Version 0.17.0 fixes the issue.

Impact

Vector 3.x

CVSS:3.1/AV:A/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H CVSS v3.1 Severity and Metrics:

Base Score: 9.00 CRITICAL
Vector: CVSS:3.1/AV:A/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H

Attack Vector (AV): Adjacent
Attack Complexity (AC): Low
Privileges Required (PR): Low
User Interaction (UI): None
Scope (S): Changed
Confidentiality (C): High
Integrity (I): High
Availability (A): High