{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-103091","assignerOrgId":"14ed7db2-1595-443d-9d34-6215bf890778","state":"PUBLISHED","assignerShortName":"Google","dateReserved":"2026-09-30T01:36:24.048Z","datePublished":"2026-10-19T02:24:35.225Z","dateUpdated":"2026-10-19T17:44:31.625Z"},"containers":{"cna":{"providerMetadata":{"orgId":"14ed7db2-1595-443d-9d34-6215bf890778","shortName":"Google","dateUpdated":"2026-10-19T02:24:35.225Z"},"title":"Insecure Default Policy and Unrestricted OIDC Enrollment in Google OSS Agent Mesh (SAM)","datePublic":"2026-09-06T16:01:00.000Z","problemTypes":[{"descriptions":[{"lang":"en","cweId":"CWE-862","description":"CWE-862 Missing Authorization","type":"CWE"}]},{"descriptions":[{"lang":"en","cweId":"CWE-1188","description":"CWE-1188 Initialization of a Resource with an Insecure Default","type":"CWE"}]},{"descriptions":[{"lang":"en","cweId":"CWE-306","description":"CWE-306 Missing Authentication for Critical Function","type":"CWE"}]},{"descriptions":[{"lang":"en","cweId":"CWE-863","description":"CWE-863 Incorrect Authorization","type":"CWE"}]},{"descriptions":[{"lang":"en","cweId":"CWE-200","description":"CWE-200 Exposure of Sensitive Information to an Unauthorized Actor","type":"CWE"}]}],"impacts":[{"capecId":"CAPEC-180","descriptions":[{"lang":"en","value":"CAPEC-180 Exploiting Incorrectly Configured Access Control Security Levels"}]},{"capecId":"CAPEC-122","descriptions":[{"lang":"en","value":"CAPEC-122 Privilege Abuse"}]}],"affected":[{"vendor":"Google","product":"SAM","packageName":"github.com/google/sam","versions":[{"status":"affected","version":"0.1.0-alpha.1","lessThan":"0.1.0-alpha.9","versionType":"semver"}],"defaultStatus":"unaffected"}],"descriptions":[{"lang":"en","value":"Missing Authorization (CWE-862) and Initialization of a Resource with an Insecure Default (CWE-1188) in the MCP proxy (HandleStreamPassThrough in mcp_service.go) and OIDC registration flow (GET /info and POST /register in internal/controlplane/server.go) in Google OSS Agent Mesh (SAM) versions 0.1.0-alpha.1 through 0.1.0-alpha.8 allow a remote attacker to self-enroll into the mesh and invoke arbitrary tools across all connected MCP backend nodes. Because GET /info publicly discloses OIDC configuration, POST /register auto-enrolls any valid OIDC token holder without claim filtering or ban checks, and the default policy binds sam:system:authenticated to wildcard services and targets, an attacker can obtain a mesh credential with full read, write, and execution access on backend services. Users should upgrade to version 0.1.0-alpha.9 or later, which enforces a fail-closed default policy, explicit policy-binding requirements on enrollment, and ban checks.","supportingMedia":[{"type":"text/html","base64":false,"value":"<p>Missing Authorization (CWE-862) and Initialization of a Resource with an Insecure Default (CWE-1188) in the MCP proxy (HandleStreamPassThrough in mcp_service.go) and OIDC registration flow (GET /info and POST /register in internal/controlplane/server.go) in Google OSS Agent Mesh (SAM) versions 0.1.0-alpha.1 through 0.1.0-alpha.8 allow a remote attacker to self-enroll into the mesh and invoke arbitrary tools across all connected MCP backend nodes. Because GET /info publicly discloses OIDC configuration, POST /register auto-enrolls any valid OIDC token holder without claim filtering or ban checks, and the default policy binds sam:system:authenticated to wildcard services and targets, an attacker can obtain a mesh credential with full read, write, and execution access on backend services. Users should upgrade to version 0.1.0-alpha.9 or later, which enforces a fail-closed default policy, explicit policy-binding requirements on enrollment, and ban checks.</p>"}]}],"references":[{"url":"https://github.com/google/sam/security/advisories/GHSA-cgmg-9xf6-rrgw","tags":["vendor-advisory"]},{"url":"https://github.com/google/sam/releases/tag/v0.1.0-alpha.9","tags":["release-notes"]}],"metrics":[{"format":"CVSS","scenarios":[{"lang":"en","value":"GENERAL"}],"cvssV4_0":{"attackVector":"NETWORK","attackComplexity":"LOW","attackRequirements":"NONE","privilegesRequired":"NONE","userInteraction":"NONE","vulnConfidentialityImpact":"HIGH","subConfidentialityImpact":"NONE","vulnIntegrityImpact":"HIGH","subIntegrityImpact":"NONE","vulnAvailabilityImpact":"HIGH","subAvailabilityImpact":"NONE","exploitMaturity":"NOT_DEFINED","Safety":"NOT_DEFINED","Automatable":"NOT_DEFINED","Recovery":"NOT_DEFINED","valueDensity":"NOT_DEFINED","vulnerabilityResponseEffort":"NOT_DEFINED","providerUrgency":"NOT_DEFINED","version":"4.0","baseSeverity":"CRITICAL","baseScore":9.3,"vectorString":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N"}}],"credits":[{"lang":"en","value":"Eli Ainhorn (Noma Security)","type":"finder"}],"source":{"discovery":"EXTERNAL"},"x_generator":{"engine":"Vulnogram 1.0.2"}},"adp":[{"references":[{"url":"https://github.com/google/agentmesh/security/advisories/GHSA-cgmg-9xf6-rrgw","tags":["exploit"]}],"metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-10-19T17:43:50.321526Z","id":"CVE-2026-103091","options":[{"Exploitation":"poc"},{"Automatable":"no"},{"Technical Impact":"total"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"title":"CISA ADP Vulnrichment","providerMetadata":{"orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","shortName":"CISA-ADP","dateUpdated":"2026-10-19T17:44:31.625Z"}}]}}