HIGHCVSS v3.1 8.0Vulnerability
CVE-2026-123272
Mark3labs mcp-go before v1.2.1 contains an improper validation vulnerability in OAuthHandler.fetchServerMetadata that allows malicious MCP servers to obtain tokens for other resources by declaring arbitrary resources in well-known metadata. Attackers can declare a different MCP server as the RFC 8707 resource indicator, causing the authorization server to mint tokens the attacker replays against that resource.
Properties
- Severity
- HIGH
- Nvd fetched at
- 2026-11-06T06:16:30.423848+00:00
- Cvss severity
- HIGH
- Cvss score
- 8
- Retrieved at
- 2026-11-06T06:17:09+00:00
- Score
- 8
- Cvss version
- 3.1
- Last source
- NVD
- Cve id
- CVE-2026-123272
- Cvss vector
- CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:H/I:H/A:N
- First seen by Signal
- 2026-11-05T22:06:44+00:00
- Name
- CVE-2026-123272
- Vector
- CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:H/I:H/A:N
- Published at
- 2026-11-05T19:17:20.713
- Last modified
- 2026-11-05T21:18:45.960
Related Entities (1)
HAS_WEAKNESS (1)
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