mcp-toolboxGHSA-7pf3-8xx7-rvhf
MCP Toolbox for Databases vulnerable to DNS rebinding attacks
CriticalCVE-2026-9739 · Published May 28, 2026 · updated Jul 7, 2026
Affected versions
| Package | Affected | Fixed in |
|---|---|---|
| github.com/googleapis/mcp-toolbox Go | < 1.2.0 | 1.2.0 |
Details and references
Vulnerable to DNS rebinding attacks when using SSE (http://b/499408790). During the beta phase, we implemented `allowed-origins` and `allowed-hosts` flags to align with MCP security guidelines. However, the hardcoded `Access-Control-Allow-Origin: *` header in the SSE initialization handler was inadvertently retained. This vulnerability specifically impacts users connecting via Toolbox using SSE under specification v2024-11-05.
- CVSS 4.0
- CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H
- Severity from
- GitHub (reviewed advisory)
- Weakness
- CWE-942
- Also known as
- CVE-2026-9739, GO-2026-5870
More mcp-toolbox advisories
All| Date | Advisory | Severity | Fixed in |
|---|---|---|---|
| Jun 13 | MCP Toolbox for Databases has an Origin Validation Error CVE-2026-11624Criticalfixed in 0.25.0 | Critical | 0.25.0 |
| Jun 18 | googleapis/mcp-toolbox: authentication bypass vulnerability in the generic opaque token validation path (validateOpaqueToken) CVE-2026-11717Criticalfixed in 1.4.0 | Critical | 1.4.0 |
| Jun 18 | googleapis/mcp-toolbox: authentication bypass vulnerability in the generic opaque token validation path (validateOpaqueToken) CVE-2026-11718Criticalfixed in 1.4.0 | Critical | 1.4.0 |
| Jun 18 | MCP Toolbox for Databases: authenticated authorization bypass CVE-2026-11719Highfixed in 1.4.0 | High | 1.4.0 |
| Jun 29 | MCP Toolbox HTTP tool path parameters allow traversal to unintended endpoints CVE-2026-11720Critical9.1fixed in 1.3.0 | Critical9.1 | 1.3.0 |