CVE-2026-77262

What it is

MCP Atlassian is a Model Context Protocol (MCP) server for Atlassian products (Confluence and Jira). Prior to 0.22.0, confluence_upload_attachment accepts an attacker-controlled file_path and does not apply the path restriction added for the earlier download vulnerability. A caller can traverse outside the workspace and upload arbitrary server-readable files to Confluence. The advisory traces the vulnerable input and processing flow through confluence_upload_attachment, file_path, and CVE-2026-27825, which identify the affected entry points, controls, and code paths. This issue is fixed in version 0.22.0.

At a glance

Exploitability

Can be exploited over the network without logging in. High risk of data exposure.

Exploit odds

0.6% chance of exploitation in the next 30 days (EPSS).

Fix

A patch, advisory or fixed version is referenced. Upgrade or apply it.

Timeline

1. 2026-09-22 19:16 UTC PublishedDisclosed publicly on CVE.org and NVD
2. 2026-09-29 18:59 UTC Last updatedMost recent change to the record

Details

Published

2026-09-22 19:16 UTC

Last modified

2026-09-29 18:59 UTC

Exploit probability

0.6% · EPSS, next 30 days

Weakness

CWE-22 · Path traversal

Record status

Analyzed

Affected

• mcp-atlassian Mcp Atlassian < 0.22.0

Attack profile CVSS 3.1 · 8.6

Attack vector

Network

Complexity

Low

Privileges needed

None

User interaction

None

Scope

Changed

Confidentiality

High

Integrity

None

Availability

None