CVE-2026-77260: mcp-atlassian Arbitrary Local File Read Vulnerability in Confluence and Jira
Summary
CVE-2026-77260: This is an arbitrary local file READ vulnerability on the Confluence and Jira upload_attachment tool paths. Affects mcp-atlassian versions < 0.22.0. Fixed in 0.22.0. How to fix ↓
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Background
The mcp-atlassian package is designed to facilitate interactions with Atlassian products, specifically Confluence and Jira. It provides tools for managing attachments and other resources within these platforms. However, a critical vulnerability has been identified that allows unauthorized reading of local files through the upload_attachment functionality, posing significant security risks.
Vulnerability Detail
This vulnerability arises from an insufficient validation of file paths in the upload_attachment tool of both Confluence and Jira. Specifically, the lack of constraints on the file_path parameter allows attackers to exploit the system by uploading sensitive files from the server's local file system. This could lead to the exfiltration of critical data such as system credentials, configuration files, and other sensitive information. The vulnerability has been classified as high severity, with a CVSS score of 8.3, indicating its potential impact on systems utilizing the affected package.
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 the upload functionality by setting the environment variable MCP_ATLASSIAN_UPLOAD_ALLOWED_DIR to a specific directory, which will reject absolute paths outside of it. This can be done by exporting the variable in your terminal: 'export MCP_ATLASSIAN_UPLOAD_ALLOWED_DIR=/path/to/allowed/directory'.
Conclusion
In summary, the CVE-2026-77260 vulnerability in the mcp-atlassian package poses a significant risk by allowing arbitrary local file reads in Confluence and Jira. It is crucial to update to the patched version and implement the suggested workarounds to mitigate potential security threats.
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FAQ
The vulnerability allows arbitrary local file reads through the upload_attachment functionality in Confluence and Jira, enabling attackers to access sensitive files.
Attackers could exfiltrate sensitive information such as system credentials and configuration files, leading to further security breaches.
You can use the Vulert playground at Vulert Scanner to check if your application is affected by this vulnerability without needing to sign up.
The CVSS score of this vulnerability is 8.3, indicating a high severity level.
Yes, a patch is available in version 0.22.0 of the mcp-atlassian package. It is recommended to update to this version or later.
References
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