CVE-2026-77253

Severity CVSS v4.0:

Pending analysis

Type:

CWE-22 Path Traversal

Publication date:

22/09/2026

Last modified:

28/09/2026

Description

MCP Atlassian is a Model Context Protocol (MCP) server for Atlassian products (Confluence and Jira). Prior to 0.22.0, Jira and Confluence attachment upload tools accept arbitrary local filesystem paths and send the selected bytes to Atlassian. In HTTP or multi-user deployments, a caller can cross the client-to-server filesystem boundary and disclose configuration, credentials, mounted secrets, or other files readable by the MCP process. The advisory traces the vulnerable input and processing flow through jira_upload_attachment, confluence_upload_attachment, file_path, and server-local filesystem, which identify the affected entry points, controls, and code paths. This issue is fixed in version 0.22.0.

Impact

Vector 3.x

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

Base Score: 7.10 HIGH
Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:L/A:N

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