Is CVE-2026-54450 exploited in the wild?

No. Junglewise Threat Intelligence has no report of CVE-2026-54450 being exploited in the wild.

How severe is CVE-2026-54450?

Medium severity, with a CVSS score of 4, published 15 September 2026.

Which products and versions are affected?

github.com/stacklok/toolhive (Go) <= 0.29.0, SEMVER:introduced=0,fixed=0.29.1; Stacklok ToolHive <= 0.29.0.

Is there a fix for CVE-2026-54450?

Yes. github.com/stacklok/toolhive (Go): upgrade to 0.29.1 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

How is CVE-2026-54450 attacked?

It is attacked over the network, in a software library.

Am I affected by CVE-2026-54450?

Check whether you run github.com/stacklok/toolhive (Go) or Stacklok ToolHive at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

CVE-2026-54450: Stacklok ToolHive SSRF bypass via IPv6 NAT64 ranges

Q: Is there a fix for CVE-2026-54450?

Yes. github.com/stacklok/toolhive (Go): upgrade to 0.29.1 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

Q: How is CVE-2026-54450 attacked?

It is attacked over the network, in a software library.

Q: Am I affected by CVE-2026-54450?

Check whether you run github.com/stacklok/toolhive (Go) or Stacklok ToolHive at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

CVE-2026-54450 · Severity: medium · CVSS 4 · Published 2026-09-15

ToolHive, a tool for managing developer workflows and OAuth integrations, contains a security flaw in how it validates network addresses. In certain cloud and container environments (specifically those using IPv6 NAT64), an attacker can bypass security filters to probe internal network services that should be private. While this does not directly allow for data theft, it enables an attacker to map out a company's internal network infrastructure.

Technologies: github.com/stacklok/toolhive (Go), Stacklok ToolHive. Vendors: Go, Stacklok.

Quick answers

Is CVE-2026-54450 exploited in the wild?: No. Junglewise Threat Intelligence has no report of CVE-2026-54450 being exploited in the wild.
How severe is CVE-2026-54450?: Medium severity, with a CVSS score of 4, published 15 September 2026.
Which products and versions are affected?: github.com/stacklok/toolhive (Go) <= 0.29.0, SEMVER:introduced=0,fixed=0.29.1; Stacklok ToolHive <= 0.29.0.
Is there a fix for CVE-2026-54450?: Yes. github.com/stacklok/toolhive (Go): upgrade to 0.29.1 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
How is CVE-2026-54450 attacked?: It is attacked over the network, in a software library.
Am I affected by CVE-2026-54450?: Check whether you run github.com/stacklok/toolhive (Go) or Stacklok ToolHive at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

How to fix

github.com/stacklok/toolhive (Go): upgrade to 0.29.1 or later
```
go get github.com/stacklok/toolhive@v0.29.1
```

Technical details

A Server-Side Request Forgery (SSRF) vulnerability exists in ToolHive's `networking.IsPrivateIP` utility due to an incomplete list of reserved CIDR blocks. The guard fails to include IPv6 NAT64 prefixes (64:ff9b::/96 and 64:ff9b:1::/48), which are used to translate IPv6 addresses to IPv4. An attacker can provide a URL that resolves to a NAT64-encoded private IPv4 address (like the cloud metadata service 169.254.169.254), bypassing the filter. The impact is limited to blind internal reachability probing because the primary entry point (CIMD fetcher) enforces HTTPS with TLS verification and does not reflect response bodies. The vulnerability is fixed in version 0.29.1.

Affected products

Stacklok ToolHive <= 0.29.0

Identifiers

CVE-2026-54450
GHSA-pph6-vfjv-vpjw
GO-2026-5996

Timeline

2026-06-04: advisory: Initial GitHub Advisory published
2026-07-15: advisory: Advisory updated with CVE-2026-54450
2026-07-15: patched: Fix released in version 0.29.1

References

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