sooperset mcp-atlassian up to 0.21.x Attachment validate_safe_path base_dir path traversal

Summaryinfo

A vulnerability was found in sooperset mcp-atlassian up to 0.21.x. It has been classified as critical. This vulnerability affects the function validate_safe_path of the component Attachment Handler. Performing a manipulation of the argument base_dir results in path traversal. This vulnerability is cataloged as CVE-2026-77271. It is possible to initiate the attack remotely. There is no exploit available. Upgrading the affected component is recommended.

Detailsinfo

A vulnerability classified as critical has been found in sooperset mcp-atlassian up to 0.21.x. This affects the function validate_safe_path of the component Attachment Handler. The manipulation of the argument base_dir with an unknown input leads to a path traversal vulnerability. CWE is classifying the issue as 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. This is going to have an impact on confidentiality, integrity, and availability. The summary by CVE is:

MCP Atlassian is a Model Context Protocol (MCP) server for Atlassian products (Confluence and Jira). Prior to 0.22.0, validate_safe_path defaults its base directory to os.getcwd(), and affected Confluence attachment call sites omit base_dir, allowing attacker-selected writes within the working directory. This Python module overwrite can provide code execution when the application later imports the modified module, bypassing the remediation tracked as CVE-2026-27825. This issue is fixed in version 0.22.0.

The advisory is shared at github.com. This vulnerability is uniquely identified as CVE-2026-77271 since 08/20/2026. The exploitability is told to be easy. It is possible to initiate the attack remotely. Technical details are known, but no exploit is available. MITRE ATT&CK project uses the attack technique T1006 for this issue.

Upgrading to version 0.22.0 eliminates this vulnerability.

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Productinfo

Type

• Artificial Intelligence Software

Vendor

• sooperset

Name

• mcp-atlassian

Version

• 0.1
• 0.2
• 0.3
• 0.4
• 0.5
• 0.6
• 0.7
• 0.8
• 0.9
• 0.10
• 0.11
• 0.12
• 0.13
• 0.14
• 0.15
• 0.16
• 0.17
• 0.18
• 0.19
• 0.20
• 0.21

Website

• Product: https://github.com/sooperset/mcp-atlassian/

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Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

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