CVE-2026-58197 — ToolHive: containerized MCP servers can reach host services via host.docker.internal, enabling lateral movement
ToolHive is a utility designed to simplify the deployment and management of Model Context Protocol servers. Prior to ToolHive CLI 0.30.1 and ToolHive Studio 0.38.0, locally run MCP server containers use the default network permission profile without network isolation, permitting access to host.docker.internal while ToolHive API and MCP proxy endpoints are reachable without authentication. A malicious or compromised MCP server can use the Docker gateway to contact host-local services, other ToolHive-managed MCP proxies, or the ToolHive control plane without escaping the container. This access can expose data and logs, invoke sibling MCP tools, alter process or workload state, and disrupt services. ToolHive Studio additionally sends network_isolation as false and overrides the backend's secure isolation default. This issue is fixed in ToolHive CLI 0.30.1 and ToolHive Studio 0.38.0.
Who exploits it and how urgent it is
A 0–100 score combining confirmed exploitation, ransomware and APT use, public exploits, EPSS and severity.
How the score was calculated
- EPSS 0.4% (30-day exploitation probability)+4
- Technical severity (high)+6
- CISA SSVC: exploitation "poc"+5
The score orders the patch queue; it does not replace your asset context (internet exposure, criticality, compensating controls).
Triage
Is it exploited, how likely is exploitation, what does it touch, and how severe do the sources call it.
CISA SSVC assessment CISA
Three decision points CISA publishes for the CVEs it assesses (SSVC 2.0.3). A stakeholder decision, not a severity score.
Remediation
Fixes and mitigations documented by the sources — linked to the original advisory.
No fix documented by the sources we poll. That does not mean none exists: check the vendor advisory.
First 24 hours
Ordered from the record’s own fields — exposure first, because you cannot patch what you have not found. A rule-generated starting point.
- Identify exposed assets running the affected vendor/product/version combinations (Stacklok Toolhive, Stacklok Toolhive-studio).
- No fix documented in the sources: reduce exposure and monitor the vendor advisory.
- Exploitation requires user interaction: tighten email/web filtering and warn affected users.
- Search available logs for exploit probes matching the vulnerability class (access control), errors and authentication anomalies.
Affected scope
Vendor, product and versions as the sources word them.
| Vendor | Product | Versions | Status | Source |
|---|---|---|---|---|
| Stacklok | Toolhive | version < 0.30.1 | Vulnerable | CVE Program (cve.org) e CISA ADP |
| Stacklok | Toolhive-studio | version < 0.38.0 | Vulnerable | CVE Program (cve.org) e CISA ADP |
Attack characteristics
The CVSS vector, decoded. It describes the attack, not your exposure to it.
Every base score collected
Sources score independently and may disagree; each row says who scored it and under which version.
| Score | Version | Severity | Expl. | Impact | Scored by |
|---|---|---|---|---|---|
| 8.8 | CVSS 3.1 | High | 2.1 | 6.0 | security-advisories@github.com via NIST National Vulnerability Database |
| 8.8 | CVSS 3.1 | High | — | — | GitHub_M via CVE Program (cve.org) e CISA ADP |
CVSS:3.1/AV:A/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H (score shown at the top: security-advisories@github.com) Weakness MITRE
Weakness class according to MITRE’s CWE catalog.
Detection
Read off the CVSS vector and the weakness class. Starting points, not tested rules.
- Audit administrative actions and access to resources outside each user’s normal pattern.
Timeline
What happened to this CVE, newest first.
- 2026
- Affected products added · stacklok/toolhive, stacklok/toolhive-studio
- SSVC assessment updated
- Record published
- CVSS changed · 8.8
- Source status changed · → Deferred
- Record created in this database
- CVE published
Source activity
Repeated readings are counted rather than listed.
- 1× Official description updated · Oct 15, 2026 – Oct 15, 2026
References
7 on the record
- github.com/stacklok/toolhive/security/advisories/GHSA-qg2g-g9w3-m5h8
- github.com/stacklok/toolhive-studio/pull/2469
- github.com/stacklok/toolhive-studio/releases/tag/v0.38.0
- github.com/stacklok/toolhive/commit/d8f40cb1599b8bf66657f2dfff15bfbfc236e712
- github.com/stacklok/toolhive-studio/commit/968182d7f3ee1e55123369e66ad88f8212811
- github.com/stacklok/toolhive/releases/tag/v0.30.1
- github.com/stacklok/toolhive/pull/5583
Elsewhere on this site
Related CVEs (same products)
- Medium CVE-2026-58196 ToolHive: SSRF in remote MCP server authentication discovery (host-side, bypasses container isolation) Sep 15, 2026
- Low CVE-2026-54450 ToolHive: SSRF guard misses IPv6 NAT64 ranges (64:ff9b::/96, 64:ff9b:1::/48), allowing metadata/internal access behind a NAT64 gateway Sep 15, 2026
Not in any source we poll
Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.
- No fixed version, patch or mitigation documented.
- No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
- No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
- No exploit packet captures, log samples, or incident case IDs supplied.
Answered from this record
Text assembled only from the fields above — no additional claims.
What should defenders know first?
CVE-2026-58197 is "ToolHive: containerized MCP servers can reach host services via host.docker.internal, enabling lateral movement", rated High. It affects Toolhive (Stacklok); versions are in the scope table. It is not in CISA KEV, which does not rule out exploitation. CVSS 8.8 describes technical severity. EPSS 0.37% estimates the probability of exploitation in 30 days; neither replaces your asset context. First verify whether exposed or business-critical assets run the affected versions, apply vendor fixes or mitigations, and preserve logs for review.
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