CVE-2026-77259: MCP Atlassian: Arbitrary file read via confluence_upload_attachment allows exfiltration of server credentials
Missing path validation in confluence_upload_attachment allows any authenticated MCP client to read arbitrary files from the server filesystem and exfiltrate their contents to Confluence. On Linux deployments, /proc/self/environ yields all runtime secrets in a single call.
References
- github.com/advisories/GHSA-6cr4-ccf3-x7h4
- github.com/sooperset/mcp-atlassian/commit/b041733473f95119dd539542a43c280737a8e460
- github.com/sooperset/mcp-atlassian/pull/1448
- github.com/sooperset/mcp-atlassian/releases/tag/v0.22.0
- github.com/sooperset/mcp-atlassian/security/advisories/GHSA-6cr4-ccf3-x7h4
- nvd.nist.gov/vuln/detail/CVE-2026-77259
Code Behaviors & Features
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