{"id":"CVE-2026-54450","url":"https://www.cyber-defence.io/tools/cve/CVE-2026-54450","generatedAt":"2026-10-28T00:20:25.775Z","title":"Prior to 0.29.1, networking.IsPrivateIP in pkg/networking/utilities.go omits the IPv6 NAT64 prefixes 64:ff9b::/96 and 64:ff9b:1::/48, so NAT64 addresses embedding private, loopback, or link-local IPv4 targets are classified as public and allowed.","description":"ToolHive is a utility designed to simplify the deployment and management of Model Context Protocol (MCP) servers. Prior to 0.29.1, networking.IsPrivateIP in pkg/networking/utilities.go omits the IPv6 NAT64 prefixes 64:ff9b::/96 and 64:ff9b:1::/48, so NAT64 addresses embedding private, loopback, or link-local IPv4 targets are classified as public and allowed. The most direct attacker-controlled path begins when an external OAuth client supplies a client_id URL that CIMDStorageDecorator.GetClient routes through FetchClientMetadataDocument in pkg/oauthproto/cimd/fetch.go; protectedDialerControl in pkg/networking/http_client.go and validateHost in pkg/skills/gitresolver/reference.go share the defective classification but use operator-controlled or user-controlled destinations. On a ToolHive host behind a NAT64/DNS64 gateway, the gateway translates an allowed address such as 64:ff9b:1::a9fe:a9fe to 169.254.169.254, permitting blind probing of internal TCP or TLS reachability. The attacker-controlled CIMD path requires HTTPS, verifies certificates, and does not reflect response bodies, so the established impact is an internal reachability oracle rather than metadata credential exfiltration; the webhook client is not affected because it does not use this IP guard. This issue is fixed in version 0.29.1.","published":"2026-09-15T16:17:14.000Z","lastModified":"2026-09-30T17:51:56.000Z","status":"Deferred","sourceIdentifier":"security-advisories@github.com","cvss":{"version":"4.0","score":2.9,"severity":"LOW","vector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N/E:P/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/M"},"cwe":["CWE-918"],"affected":[],"epss":{"score":0.00327,"percentile":0.25531,"date":"2026-10-26","history":[]},"kev":{"listed":false},"exploits":{"count":0,"verified":false,"firstPublished":null,"source":"Exploit-DB (https://gitlab.com/exploit-database/exploitdb)","entries":[]},"verdict":{"level":"low","text":"Lower severity and a low EPSS score (0.33%). Track it; it rarely justifies an emergency change on its own."},"changes":[],"references":[{"url":"https://github.com/stacklok/toolhive/commit/26912af453d2040787983dbc9ab93a9019ec0468","source":"security-advisories@github.com"},{"url":"https://github.com/stacklok/toolhive/releases/tag/v0.29.1","source":"security-advisories@github.com"},{"url":"https://github.com/stacklok/toolhive/security/advisories/GHSA-pph6-vfjv-vpjw","source":"security-advisories@github.com"}],"sources":{"nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-54450","epss":"https://www.first.org/epss/","kev":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog","exploitdb":"https://www.exploit-db.com/"},"licence":"CC BY 4.0 — link back to the CVE Explorer if you publish the results; upstream data remains subject to its own terms."}