CVE-2026-77266

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, 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.

Impact

Vector 3.x

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

Base Score: 6.50 MEDIUM
Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/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): None
Availability (A): None