CVE-2026-77260
Received Received - Intake

Path Traversal in MCP Atlassian Server

Publication date: 2026-09-22

Last updated on: 2026-09-22

Assigner: GitHub, Inc.

Description
MCP Atlassian is a Model Context Protocol (MCP) server for Atlassian products (Confluence and Jira). Prior to 0.22.0, the Confluence and Jira upload_attachment implementations accept an unconstrained file_path and open the referenced server-local file. A permitted MCP caller can upload sensitive host files to an Atlassian destination and then retrieve their contents. The advisory traces the vulnerable input and processing flow through 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.

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Meta Information

Published
2026-09-22
Last Modified
2026-09-22
Generated
2026-09-22
AI Q&A
2026-09-22
EPSS Evaluated
N/A
NVD
CVE-2026-77260
EUVD
EUVD-2026-84630

Affected Vendors & Products

Showing 3 associated CPEs
Vendor Product Version / Range
atlassian confluence to 0.22.0 (exc)
atlassian jira to 0.22.0 (exc)
atlassian mcp_atlassian to 0.22.0 (exc)

Helpful Resources

Exploitability

CWE
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KEV
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CWE ID Description
CWE-22 The product uses external input to construct a pathname that is intended to identify a file or directory that is located underneath a restricted parent directory, but the product does not properly neutralize special elements within the pathname that can cause the pathname to resolve to a location that is outside of the restricted directory.

Attack-Flow Graph

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Executive Summary

CVE-2026-77260 is an arbitrary local file read vulnerability in the MCP Atlassian package versions before 0.22.0. It affects the upload_attachment functionality for Confluence and Jira, where unconstrained file paths allow reading sensitive server files. The file_path parameter is not validated, enabling access to absolute paths like /etc/shadow or ~/.ssh/id_rsa.

Detection Guidance

Check if the mcp-atlassian package version is below 0.22.0 using package managers like pip. Inspect server logs for unusual attachment uploads or file access patterns, particularly for absolute paths or sensitive files like /etc/shadow or ~/.ssh/id_rsa.

Impact Analysis

An attacker can exploit this to upload and retrieve sensitive files from the server, such as credentials or configuration files. This can be done via prompt injection in LLM deployments or direct HTTP calls without authentication. The impact includes potential data breaches and unauthorized access to critical system files.

Compliance Impact

This vulnerability could lead to non-compliance with GDPR, HIPAA, and other regulations by enabling unauthorized access to personal or sensitive data. Exfiltration of credentials or configuration files may violate data protection requirements, leading to legal and financial penalties.

Mitigation Strategies

Upgrade the mcp-atlassian package to version 0.22.0 or later. Restrict file upload paths by configuring a safe directory validation mechanism. Set an environment variable to allow uploads only from specific directories. Review and remove any unauthorized attachments uploaded via this vulnerability.

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