CVE-2026-77262

MCP Atlassian: Path Traversal / Arbitrary File Read in confluence_upload_attachment MCP tool (incomplete fix of CVE-2026-27825)

Published Sep 22, 2026 CVSS 3.1 · 8.6 High EPSS < 1% KEV · Not listed
Description
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.

Analysis

AI-generated

Technical impact

The confluence_upload_attachment endpoint accepts an attacker-controlled file_path and does not enforce the path restriction that was added for earlier download vulnerabilities. An attacker can provide a crafted path that traverses outside the intended workspace, allowing the system to read any server‑side file that it has permission to read and to upload arbitrary files to Confluence. This can lead to confidential data disclosure and to the placement of malicious files that may be processed or served by Confluence, potentially compromising integrity and confidentiality of the system.

Affected Systems

The vulnerability exists in the Sooperset MCP Atlassian server for Atlassian products (Confluence and Jira). All releases before version 0.22.0 are affected; the fix is delivered in 0.22.0.

Risk and Exploitability

The vulnerability carries a CVSS score of 8.6, indicating a high impact if exploited. EPSS data is not available, and it is not listed in CISA's KEV catalog. The likely attack vector requires the ability to send a request to the vulnerable endpoint with a crafted file_path, typically via an authenticated user action or API call. Due to the lack of a publicly known exploit, the probability of exploitation in the near term is uncertain, but the impact warrants prompt remediation.

Remediation

No solution or workaround provided in the CVE record.

OpenCVE Recommended Actions

  • Upgrade Sooperset MCP Atlassian to release 0.22.0 or later
  • If an upgrade is not immediately feasible, restrict access to the confluence_upload_attachment endpoint to only trusted or administrative users
  • Implement additional validation on incoming file_path parameters to reject traversal attempts before reaching application logic

Generated by OpenCVE AI on September 22, 2026 at 19:35 UTC.

Tracking

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Advisories

Source ID Title
Github GHSA Github GHSA GHSA-p6hp-93wp-fh6p MCP Atlassian: Path Traversal / Arbitrary File Read in confluence_upload_attachment MCP tool (incomplete fix of GHSA-xjgw-4wvw-rgm4)
History
Type Values Removed Values Added
First Time appeared Mcp-atlassian
Mcp-atlassian mcp Atlassian
CPEs cpe:2.3:a:mcp-atlassian:mcp_atlassian:*:*:*:*:*:*:*:*
Vendors & Products Mcp-atlassian
Mcp-atlassian mcp Atlassian
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'poc', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Type Values Removed Values Added
First Time appeared Sooperset
Sooperset mcp-atlassian
Vendors & Products Sooperset
Sooperset mcp-atlassian
Type Values Removed Values Added
Description 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.
Title MCP Atlassian: Path Traversal / Arbitrary File Read in confluence_upload_attachment MCP tool (incomplete fix of CVE-2026-27825)
Weaknesses CWE-22
References
Metrics cvssV3_1

{'score': 8.6, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:N/A:N'}

Weaknesses
  • CWE-22

    Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')

Sources

Status
PUBLISHED
Assigner
GitHub_M
Published
Updated
Sep 28, 2026, 5:20 PM
Reserved
Aug 20, 2026, 7:02 PM
Status
Analyzed
Published
Sep 22, 2026, 7:16 PM
Modified
Sep 29, 2026, 6:59 PM