{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-90898", "assignerOrgId": "48a46f29-ae42-4e1d-90dd-c1676c1e5e6d", "state": "PUBLISHED", "assignerShortName": "JFROG", "dateReserved": "2026-09-14T10:13:28.161Z", "datePublished": "2026-09-14T10:18:53.454Z", "dateUpdated": "2026-09-14T11:19:46.276Z"}, "containers": {"cna": {"providerMetadata": {"orgId": "48a46f29-ae42-4e1d-90dd-c1676c1e5e6d", "shortName": "JFROG", "dateUpdated": "2026-09-14T10:18:53.454Z"}, "title": "Bifrost unauthenticated remote code execution via MCP stdio client registration", "problemTypes": [{"descriptions": [{"lang": "en", "cweId": "CWE-306", "description": "CWE-306 Missing Authentication for Critical Function", "type": "CWE"}]}, {"descriptions": [{"lang": "en", "cweId": "CWE-284", "description": "CWE-284 Improper Access Control", "type": "CWE"}]}], "affected": [{"vendor": "maximhq", "product": "Bifrost", "platforms": ["Linux", "macOS"], "collectionURL": "https://github.com/maximhq/bifrost", "packageName": "github.com/maximhq/bifrost/transports", "repo": "git://github.com/maximhq/bifrost", "modules": ["transports/bifrost-http", "core/mcp"], "programFiles": ["transports/bifrost-http/handlers/mcp.go", "transports/bifrost-http/handlers/middlewares.go"], "versions": [{"status": "affected", "version": "0", "lessThan": "2.1.0", "versionType": "semver"}], "defaultStatus": "unaffected"}], "descriptions": [{"lang": "en", "value": "Bifrost registers MCP clients through its management API. A stdio client is a command plus args. Bifrost starts that program in the gateway the moment the client is added. No MCP handshake required.\n\n\n\nThe default is governance.auth_config.is_enabled=false. Auth off means every caller is a local admin. One unauthenticated POST /api/mcp/client is enough to run a program as the Bifrost process user (appuser on the official image).\n\n\n\n\u00a0transports/v2.1.0 refuses an unauthenticated stdio registration with 403. transports/v2.0.0 still allows it.", "supportingMedia": [{"type": "text/html", "base64": false, "value": "<p>Bifrost registers MCP clients through its management API. A stdio client is a command plus args. Bifrost starts that program in the gateway the moment the client is added. No MCP handshake required.</p><p>The default is governance.auth_config.is_enabled=false. Auth off means every caller is a local admin. 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The 1.6.x line through 1.6.11 and transports/v2.0.0 do not include this change.</p>", "base64": false}]}], "references": [{"url": "https://github.com/maximhq/bifrost/pull/6757", "name": "PR #6757: refuse unauthenticated stdio MCP registration", "tags": ["patch"]}, {"url": "https://github.com/maximhq/bifrost/commit/12e170352bd25eab1ae9ba16611f1797d1fd8fdc", "name": "Merge commit for PR #6757", "tags": ["patch"]}, {"url": "https://github.com/maximhq/bifrost/releases/tag/transports/v2.1.0", "name": "Bifrost HTTP v2.1.0 (first release containing the fix)", "tags": ["release-notes"]}, {"url": "https://github.com/maximhq/bifrost", "name": "Bifrost repository", "tags": ["product"]}], "workarounds": [{"lang": "en", "value": "Set governance.auth_config.is_enabled to true, use strong administrator credentials, and firewall the management listener.", "supportingMedia": [{"type": "text/html", "value": "<p>Set governance.auth_config.is_enabled to true, use strong administrator credentials, and firewall the management listener.&nbsp;</p>", "base64": false}]}], "x_generator": {"engine": "Vulnogram 1.0.4"}, "descriptions": [{"lang": "en", "value": "Bifrost registers MCP clients through its management API. 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{"affected": [{"configurations": [{"platform": ["linux", "macos"], "status": "affected", "versions": {"scheme": "semver", "value": "[0,2.1.0)"}}], "enrichment": {"confidence": 100.0, "confidence_source": "matching", "scores": [{"score": 100.0, "source": "matching"}]}, "original": {"product": "Bifrost", "source": "cna", "vendor": "maximhq"}, "product": "bifrost", "vendor": "maximhq"}], "created": "2026-09-14T12:00:13.242813+00:00", "updated": "2026-09-14T12:00:13.242837+00:00", "vendors": ["maximhq", "maximhq$PRODUCT$bifrost"]}