CVE-2026-63127: RMCP OAuth metadata validation flaw
Attack on AI2 Disclosed vulnerabilityInfrastructure vulnerability
An OAuth metadata validation flaw exists in the RMCP SDK for the Model Context Protocol prior to version 2.0.0. A malicious MCP server can exploit this to cause clients to connect to an unintended authorization server.
disclosed CVENo confirmed exploitation, so this record is tracked as a disclosed vulnerability and not counted as an incident. It moves into the counts if CISA or the vendor confirms exploitation. Why
Details
- type
- Attack on AIAn AI model, agent or AI-powered product was the thing exploited, abused or leaked.
- categories
- Infrastructure vulnerabilityCVEs and advisories in AI frameworks, inference servers, MCP servers, AI developer tools and hosting stacks.
- Infrastructure vulnerability
- owasp llm top 10
- mitre atlas
- no technique for these categoriesBoth rows are derived from the type and categories (OWASP 2025 edition, ATLAS release 2026.09), not classified per record. How
- severity
- 2 · Disclosed vulnerabilityCVE or vendor advisory, patched or patchable, no confirmed exploitation.
- targets
- Framework / tooling
- products
- RMCP
- incident date
- 16 Sep 2026
- first reported
- 16 Sep 2026
- origin
- NVDVulnerability record from NVD / the GitHub Advisory Database. This product uses the NVD API but is not endorsed or certified by the NVD.
- classifier confidence
- 0.95 · published at or above 0.80; see the methodology
- tags
- CVE-2026-63127 · oauth · mcp
- record
- created 2026-10-18 06:33Z · updated 2026-10-18 06:33Z · json
Sources · 1
- 2026-09-16CVE-2026-63127: RMCP is an official Rust SDK for the Model Context Protocol.NVD · nvd.nist.gov/vuln/detail/CVE-2026-63127
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