---
cve: "CVE-2026-11720"
severity: "CRITICAL"
cvss: 9.3
epss: "38%"
vendor: "Google"
kev: false
exploited: false
published: "2026-06-29 18:16:36"
tags: [cve, security, critical]
source: tsecurity.de CVE-Dossier
exported: "2026-09-08T16:50:30+02:00"
---

# CVE-2026-11720

> 9.3 CRITICAL · 🧪 PoC

## Beschreibung

A path traversal vulnerability exists in the HTTP tool URL builder of googleapis/mcp-toolbox.

When constructing downstream API requests, the URL builder substitutes user-controlled pathParams into the configured tool path and parses the resulting string as a relative URL. While it checks that the input does not alter the scheme, host, or user info, it relies on ResolveReference for the final URL resolution. Because dot segments (../) are normalized during this resolution step, an attacker can supply path parameters containing directory traversal sequences to escape the operator-configured path scope. This allows the client to coerce the toolbox into making requests to unintended endpoints on the same target host while forwarding the toolbox's configured credentials (e.g., bypassing a restricted path like /api/v1/users/{{.id}} to reach /admin/secrets).

## CVSS-Vektor

```
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N
```

| Metrik | Wert | Bewertung |
|---|---|---|
| AV Angriffsvektor | Netzwerk | bad |
| AC Komplexität | Gering | bad |
| PR Privilegien | Keine | bad |
| UI Interaktion | Keine | bad |

## Patch verfügbar (OSV)

- b0010060a939455d91e4f8ba62dc3e72b1892469 (Commit)

## Referenzen

- <https://github.com/googleapis/mcp-toolbox/pull/3218>

---
_Exportiert aus dem [tsecurity.de CVE-Dossier](https://tsecurity.de/cve?cve=CVE-2026-11720) · Datenquellen: EUVD (ENISA), NVD, OSV, CISA KEV, FIRST EPSS, Exploit-DB, BSI BITS_