CVE-2026-77246
highMCP Atlassian is a Model Context Protocol (MCP) server for Atlassian products (Confluence and Jira).
Vendor / product: Mcp-atlassian — mcp atlassian
MCP Atlassian is a Model Context Protocol (MCP) server for Atlassian products (Confluence and Jira). Prior to 0.22.0, an HTTP transport deployment with READ_ONLY_MODE=false accepts a request without an Authorization identity and permits attacker-controlled Atlassian service headers, including X-Atlassian-Confluence-Url, to select a public attacker hostname or one allowed by MCP_ALLOWED_URL_DOMAINS. A caller can then invoke confluence_upload_attachment or the Jira attachment variant in src/mcp_atlassian/jira/attachments.py with a server-local file_path and cause the MCP process to send the file to the selected attachment endpoint. This issue is fixed in version 0.22.0.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:N/A:N Affected products
Weakness classification (CWE)
Source: NVD / CISA. “NVD-CWE-Other” and “NVD-CWE-noinfo” mean NVD could not assign a specific weakness.
Mitigation & advisories
References
- https://github.com/sooperset/mcp-atlassian/commit/b041733473f95119dd539542a43c280737a8e460 security-advisories@github.com
- https://github.com/sooperset/mcp-atlassian/pull/1448 security-advisories@github.com
- https://github.com/sooperset/mcp-atlassian/releases/tag/v0.22.0 security-advisories@github.com
- https://github.com/sooperset/mcp-atlassian/security/advisories/GHSA-wv8v-v4c5-v75j security-advisories@github.com
- https://github.com/sooperset/mcp-atlassian/security/advisories/GHSA-wv8v-v4c5-v75j 134c704f-9b21-4f2e-91b3-4a467353bcc0