CVE-2026-108586 — 1MCP Agent 0.20.0 through 0.39.0 OAuth Tag-Scope Bypass via Negated Tag Filter

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 ne…

Published: 2026-10-10 · CVSS: 5.3 · CVSS 4.0

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 <granted-tag> to list and invoke tools on backend MCP servers outside their granted scopes.

Original CVE JSON · STIX 2.1

Source: CVE Program · Revision 8b16575c39f1e1810c5e863010da073d2d3285e7