CVE-2026-77266

MEDIUM CVSS 3.1: 6.5 EPSS 0.44%
Updated Sep 28, 2026
Sooperset
Parameter Value
CVSS 6.5 (MEDIUM)
Affected Versions before 0.22.0
Fixed In 0.22.0
Type CWE-22 (Path Traversal)
Vendor Sooperset
Public PoC No

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.

Attack Parameters

Attack Vector
Network
Can be exploited remotely
Attack Complexity
Low
Easy to exploit
Privileges Required
Low
Basic privileges needed
User Interaction
None
No user interaction needed

Impact Assessment

Confidentiality
High
Complete data leak
Integrity
None
No data modification
Availability
None
No disruption

CVSS Vector v3.1

Weakness Type (CWE)

Vulnerable Products 1

Configuration From (including) Up to (excluding)
Mcp-Atlassian Mcp_Atlassian
cpe:2.3:a:mcp-atlassian:mcp_atlassian:*:*:*:*:*:*:*:*
— 0.22.0