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.
AI analysis
Not analysed yet.
Claude analyses new vulnerabilities after each morning's collection, most important first, up to a daily limit. The verified data on this page is complete without it.
The sources do not list affected products or versions for this vulnerability yet.
0.2%9th percentile
Bar shows rank among all scored CVEs.
Published
First publication at the source
Collected
First seen by Baba Yaga Security
Last modified
Latest change at the source