CVE-2026-77262: mcp-atlassian Path Traversal and Arbitrary File Read Vulnerability
Summary
CVE-2026-77262: mcp-atlassian exposes an MCP tool confluence_upload_attachment whose file_path argument is passed directly to open(file_path, "rb") without any path validation. Affects mcp-atlassian versions < 0.22.0. Fixed in 0.22.0. How to fix ↓
Check if this vulnerability affects your application
Upload a manifest or SBOM and we'll show whether you're affected, plus every other risky package in the same scan.
No signup required · Results in about 60 seconds
Background
mcp-atlassian is a tool designed for integration with Atlassian Confluence, allowing users to upload attachments and manage content programmatically. It is built on Python and leverages the MCP (Multi-Channel Protocol) for communication. The tool is intended to facilitate seamless interactions with Confluence, but it has a critical vulnerability that exposes it to path traversal attacks, enabling unauthorized file access.
Vulnerability Detail
The vulnerability arises from the confluence_upload_attachment MCP tool, where the file_path argument is directly passed to the open(file_path, 'rb') function without any validation. This flaw allows an attacker to read arbitrary files on the server that are accessible to the server process. If exploited, sensitive files such as /etc/passwd, AWS credentials, and SSH keys can be exfiltrated to an attacker-controlled Confluence instance. The vulnerability is particularly severe due to the default configuration of the tool, which binds to 0.0.0.0 without authentication, making it remotely exploitable without credentials. The CVSS score for this vulnerability is 8.6, indicating a high level of risk.
How To Fix
Latest published version: 0.23.1 as of 23 Oct 2026
pip install --upgrade "mcp-atlassian==0.23.1"Upgrading to it may include breaking changes; the version below is the minimum fixed release for this vulnerability.
If you need the minimum change
0.22.0
This is the first release that contains the fix.
pip install --upgrade "mcp-atlassian==0.22.0"Tip — Not sure which version your app runs? Vulert can match this fix to it. Scan free →
Workaround
As a temporary workaround, you can restrict access to the MCP tool by binding it to 127.0.0.1 instead of 0.0.0.0, or by implementing an authentication layer when exposing the tool to a non-loopback interface. This will help mitigate the risk of unauthorized access until the patch is applied.
Conclusion
The mcp-atlassian package has a critical vulnerability that allows for path traversal and arbitrary file reading. It is essential to update to the patched version to mitigate the risk of unauthorized file access. Implementing workarounds can provide temporary relief until the update is applied.
See every vulnerability recorded for mcp-atlassian →
FAQ
The vulnerability allows for path traversal and arbitrary file reading, enabling attackers to access sensitive files on the server.
You can check if your application is affected by using the Vulert playground at Vulert Scanner, which monitors open-source vulnerabilities in real-time.
If exploited, attackers can exfiltrate sensitive information such as user credentials, configuration files, and other critical data.
Yes, a patch is available in version 0.22.0 of the mcp-atlassian package. It is recommended to update to this version.
If you cannot update immediately, implement a workaround by restricting access to the MCP tool and binding it to a local interface.
References
Related vulnerabilities
Recent vulnerabilities recorded for mcp-atlassian.
