Vulnerability-Lookup

GHSA-QX8V-PQ9P-7G7V

Vulnerability from github – Published: 2026-10-19 03:31 – Updated: 2026-10-19 18:32

Details

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.

Severity

9.3 (Critical)


                  
                    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

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JSON

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{
  "affected": [],
  "aliases": [
    "CVE-2026-103091"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-200"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-10-19T03:16:58Z",
    "severity": "CRITICAL"
  },
  "details": "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.",
  "id": "GHSA-qx8v-pq9p-7g7v",
  "modified": "2026-10-19T18:32:06Z",
  "published": "2026-10-19T03:31:05Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/google/agentmesh/security/advisories/GHSA-cgmg-9xf6-rrgw"
    },
    {
      "type": "WEB",
      "url": "https://github.com/google/sam/security/advisories/GHSA-cgmg-9xf6-rrgw"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-103091"
    },
    {
      "type": "WEB",
      "url": "https://github.com/google/sam/releases/tag/v0.1.0-alpha.9"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X",
      "type": "CVSS_V4"
    }
  ]
}

CVE-2026-103091 (GCVE-0-2026-103091)

Vulnerability from cvelistv5 – Published: 2026-10-19 02:24 – Updated: 2026-10-19 17:44

Title

Insecure Default Policy and Unrestricted OIDC Enrollment in Google OSS Agent Mesh (SAM)

Summary

Severity

9.3 (Critical)


                        
                          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

SSVC

Exploitation: poc Automatable: no Technical Impact: total

CISA Coordinator · CISA-ADP (v2.0.3)

Decision recorded 2026-10-19 17:43 UTC

CWE

CWE-862 - Missing Authorization
CWE-1188 - Initialization of a Resource with an Insecure Default
CWE-306 - Missing Authentication for Critical Function
CWE-863 - Incorrect Authorization
CWE-200 - Exposure of Sensitive Information to an Unauthorized Actor

Assigner

Google CNA under the Google root

CNA scorecard B 76/100 over 35 records in the last 180 days details

References

3 references

URL	Tags
https://github.com/google/sam/security/advisories…	vendor-advisory
https://github.com/google/sam/releases/tag/v0.1.0…	release-notes
https://github.com/google/agentmesh/security/advi…	exploit

Impacted products

1 product

Vendor	Product	Version
Google	SAM	Affected: 0.1.0-alpha.1 , < 0.1.0-alpha.9 (semver)

Date Public

2026-09-06 16:01

Credits

Eli Ainhorn (Noma Security)

Show details on NVD website

JSON

To clipboard

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Sightings

Author	Source	Type	Date	Other

Nomenclature

Seen: The vulnerability was mentioned, discussed, or observed by the user.
Confirmed: The vulnerability has been validated from an analyst's perspective.
Published Proof of Concept: A public proof of concept is available for this vulnerability.
Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
Not confirmed: The user expressed doubt about the validity of the vulnerability.
Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.

Vulnerability timeline

Sightings and recorded dates, grouped by day · UTC

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The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base model, served locally by ML-Gateway. They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
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