CVE-2026-77243: MCP Atlassian: ENABLED_TOOLS / Toolset authorization bypass
ENABLED_TOOLS and TOOLSETS filters are enforced at tools/list time only. tools/call dispatches from the full unfiltered tool registry (73 tools). Any user with access to the server endpoint that knows a tool name can invoke it directly. Tool names are not secret since mcp-atlassian is open source. Any direct JSON-RPC call bypasses the restriction entirely.
READ_ONLY_MODE is not affected: it has dual enforcement at list time (_list_tools_mcp) and call time @check_write_access decorator. The developers applied the correct pattern to READ_ONLY_MODE but not to ENABLED_TOOLS or toolsets - confirming this is an implementation oversight.
References
- github.com/advisories/GHSA-3r68-hf9h-887v
- 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-3r68-hf9h-887v
- nvd.nist.gov/vuln/detail/CVE-2026-77243
Code Behaviors & Features
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