CVE-2026-77271highCWE-22CWE-94

CVE-2026-77271: high-severity vulnerability in sooperset mcp-atlassian

MCP Atlassian: Incomplete path traversal fix allows intra-CWD module overwrite and RCE (bypass of CVE-2026-27825)

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21Vexday Risk Score

No sign of exploitation. No public exploitation artifact known so far.

ssvc Trackcvss 8.3epss 0.6%
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.
CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:N/VA:N/SC:H/SI:N/SA:N
Affected products
sooperset · mcp-atlassian
Related CVEs — sooperset mcp-atlassian

In the same product, most dangerous first.

CVE-2026-27826HIGHMCP Atlassian has SSRF via unvalidated X-Atlassian-Jira-Url / X-Atlassian-Confluence-Url headersEPSS 13.9%CVE-2026-27825CRITICALMCP Atlassian has an arbitrary file write leading to arbitrary code execution via unconstrained download_path in confluence_download_attachmentEPSS 12.3%CVE-2026-77254CRITICALMCP Atlassian: Unauthenticated HTTP MCP requests can use globally configured Jira and Confluence credentialsEPSS 0.6%CVE-2026-77262HIGHMCP Atlassian: Path Traversal / Arbitrary File Read in confluence_upload_attachment MCP tool (incomplete fix of CVE-2026-27825)EPSS 0.6%CVE-2026-77243HIGHMCP Atlassian: ENABLED_TOOLS / Toolset authorization bypassEPSS 0.5%CVE-2026-124503MEDIUMsooperset mcp-atlassian io.py validate_safe_path path traversalEPSS 0.5%