MCP Inspector is Vulnerable to Potential Command Execution via XSS When Connecting to an Untrusted MCP Server
21Vexday Risk Score
No sign of exploitation. No public exploitation artifact known so far.
ssvc Trackcvss 8.6epss 0.6%
exploitation probability
0.6%top 53% of all CVEs
observed exploitation
nono source reports it
The MCP inspector is a developer tool for testing and debugging MCP servers. A cross-site scripting issue was reported in versions of the MCP Inspector local development tool prior to 0.16.6 when connecting to untrusted remote MCP servers with a malicious redirect URI. This could be leveraged to interact directly with the inspector proxy to trigger arbitrary command execution. Users are advised to update to 0.16.6 to resolve this issue.
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
Affected products
modelcontextprotocol · inspector