CVE-2026-102242: Path Traversal via Symlink Following in allowedLocalRoots in MCP Toolbox for Databases

Severity: high (CVSS 8.6 v4.0)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.4% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-09-29 · updated 2026-09-29
Weakness: CWE-22

Description

Improper link resolution (CWE-59 / CWE-22) in the allowedLocalRoots path validation in Google MCP Toolbox for Databases versions 1.2.0 through 1.9.0 allows a remote authenticated attacker with tool execution permissions to bypass directory boundary restrictions via symbolic links. Because path validation checks directories lexically without resolving symbolic links first, an attacker can access or overwrite arbitrary local files located outside the permitted root directories.

Affected products

Google MCP Toolbox for Databases (googleapis/mcp-toolbox): from 1.2.0 through 1.9.0

References

https://github.com/googleapis/mcp-toolbox/pull/3810

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