1MCP Agent (@1mcp/agent) 0.20.0 through 0.39.0 contains an incorrect authorization vulnerability that allows authenticated clients to bypass OAuth…
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.
Read at NIST National Vulnerability Database (CVE API 2.0)
- Vendor
- Anthropic
- Product
- Claude, AI / LLM tooling
- CVSS
- 5.4
- Exposure class
- AI infrastructure
Why it ranks 8 (Routine)
- CVSS 5.4 medium
- Product class: AI infrastructure
- Recency: items published within 24 hours gain 15, within 72 hours 6, within 7 days 2.