GHSA-w2j7-xxh9-9q67MediumCVSS 5.4
1MCP Agent (@1mcp/agent) 0.20.0 through 0.39.0 contains an incorrect authorization vulnerability...
🔗 CVE IDs covered (1)
📋 Description
1MCP Agent (@1mcp/agent) 0.20.0 through 0.39.0 contains an incorrect authorization vulnerability that allows authenticated clients to bypass OAuth tag-scope enforcement using negated advanced tag-filter expressions. Attackers holding a single-tag token can send a filter like not to list and invoke tools on backend MCP servers outside their granted scopes.
🔗 References (7)
- https://nvd.nist.gov/vuln/detail/CVE-2026-108586
- https://github.com/1mcp-app/agent
- https://github.com/1mcp-app/agent/blob/v0.39.0/src/sdk/legacy/transport/http/middlewares/scopeAuthMiddleware.ts#L163-L183
- https://github.com/1mcp-app/agent/blob/v0.39.0/src/transport/http/routes/inspectHelpers.ts#L79-L102
- https://hackmd.io/@haind/1mcp-negated-tag-filter-oauth-scope-bypass
- https://www.vulncheck.com/advisories/1mcp-agent-0.20.0-through-0.39.0-oauth-tag-scope-bypass-via-negated-tag-filter
- https://github.com/advisories/GHSA-w2j7-xxh9-9q67