Vulnerability-Lookup

GHSA-598G-H2VC-H5VG

Vulnerability from github – Published: 2026-06-08 23:09 – Updated: 2026-06-08 23:09

Summary

nebula-mesh: API endpoints lack ownership checks, enabling cross-operator privilege escalation

Details

The /api/v1/* route surface trusts the bearer token alone for authorisation on most endpoints. The codebase itself admits this at internal/api/hosts.go:384: "API trusts the bearer token for authorisation; per-CA ownership is enforced only in the Web layer."

The Web UI gates state-changing routes through loadAccessibleCA (internal/web/cas.go); CA-management endpoints in internal/api/cas.go ALSO have proper canAccessCA gates. The gap is on the host, network, firewall, mobile-bundle, and most operator endpoints. Combined with the per-operator CA model from ADR 0002, this gives any non-admin operator API key broad cross-tenant access — instant privilege escalation in the worst case.

Affected

All released versions prior to v0.3.4.

Exploit chain

A) Mint admin API key from any operator key (instant privilege escalation)

internal/api/operators.go:118 — handleCreateOperatorAPIKey does no admin check and no actor/target-operator ownership check. Any operator key can call it for any operator (including admins) and receive a fresh bearer.

curl -X POST -H "Authorization: Bearer <low-priv-key>" \
  https://server/api/v1/operators/<admin-id>/api-keys \
  -H 'Content-Type: application/json' -d '{"name":"oops"}'
# Returns: {"key":"<32-byte admin bearer>","entry":{...}}

Reuse the returned key for subsequent requests → full admin.

B) Cross-operator host takeover via reenroll

internal/api/hosts.go:321,330 → mintEnrollmentTokenForHost. Looks up host by URL param, mints a single-use enrollment token, returns it. No ownership check.

curl -X POST -H "Authorization: Bearer <low-priv-key>" \
  https://server/api/v1/hosts/<victim-host-id>/reenroll
# Returns: {"enrollment_token":"<uuid>",...}

Caller POSTs /api/v1/enroll with their own X25519 + Ed25519 keypairs. enroll.go:175 overwrites signing_pub_pem; SaveCertificateAndEnrollHost overwrites the cert. Legitimate agent's next signed poll fails bad_signature. Attacker now owns the victim's Nebula identity.

C) Cross-tenant CRUD on hosts, networks, firewall

The same gap applies across: - /api/v1/hosts* — create, list, get, update, delete, block, unblock - /api/v1/networks* — create, list, get - /api/v1/networks/{id}/firewall — get, PUT - /api/v1/hosts/{id}/mobile-bundle (already filed as public issue #119)

All trust bearer-auth alone. Any operator can read or mutate any other operator's resources.

Affected operator-management handlers (in addition to A)

Beyond handleCreateOperatorAPIKey (covered by A), internal/api/operators.go is missing admin gates on: - handleListOperators (line 66) — operator roster info disclosure - handleDisableOperator (line 79) — DoS / sabotage - handleEnableOperator (line 94) — re-enable disabled operators - handleRevokeOperatorAPIKey (line 157) — invalidate any operator's API keys - handleListOperatorAPIKeys (line 173) — API-key metadata disclosure

handleCreateOperator (line 26) IS properly gated (actorIsAdmin at line 27).

NOT affected (verified)

internal/api/cas.go properly gates every CA endpoint via canAccessCA (calls at lines 70, 176, 216) and admin shortcuts at lines 39, 82. An earlier description draft mistakenly listed /api/v1/cas/{id}/rotate as affected — that endpoint is properly protected. CAs are not in this gap.

Impact

Any non-admin operator → admin via one curl (A).
Any non-admin operator → ownership of any victim's hosts with cert + identity transfer (B).
Mass cross-tenant CRUD including firewall-rule mutation (C).
Any operator → disable/enable other operators, revoke their API keys, enumerate the operator roster.

CVSS 3.1: AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H — 9.6.

Suggested fix

Shared helpers in a new internal/api/authz.go, mirroring the Web layer's loadAccessibleCA:

func (s *Server) requireAdmin(w http.ResponseWriter, r *http.Request) bool
func (s *Server) requireOperatorAccess(w http.ResponseWriter, r *http.Request, operatorID string) bool
func (s *Server) requireHostAccess(w http.ResponseWriter, r *http.Request, hostID string) (*models.Host, bool)
func (s *Server) requireNetworkAccess(w http.ResponseWriter, r *http.Request, networkID string) (*models.Network, bool)

Each loads the resource, resolves its CA via *.CAID, accepts if actorIsAdmin(ctx) OR actor owns the CA. Reject 403 forbidden; audit-log api.<resource>.forbidden with the reason.

The operator-management endpoints take requireAdmin instead (operator ownership doesn't map to CA ownership).

Apply at the top of every host-, network-, firewall-, mobile-bundle-touching API handler, plus the 5 operator endpoints listed above. The legacy config-key path retains admin (preserves backward compatibility); the broader legacy-fallback question is tracked separately as issue #121.

Test matrix

admin → all operations permitted
owning non-admin → operations on owned hosts/networks permitted
non-owner non-admin → 403 + audit entry
legacy config-key → preserved (admin)
unauthenticated → existing 401 from middleware

Coordinated context

Subsumes public issue #119 (mobile-bundle authz). Issue #121 (actor.go:40 legacy-admin fallback) is a separate concern tracked independently.

Severity

9.9 (Critical)


                  
                    CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H

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{
  "affected": [
    {
      "package": {
        "ecosystem": "Go",
        "name": "github.com/juev/nebula-mesh"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "0.3.4"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2026-47724"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-862"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-06-08T23:09:02Z",
    "nvd_published_at": null,
    "severity": "CRITICAL"
  },
  "details": "The `/api/v1/*` route surface trusts the bearer token alone for authorisation on most endpoints. The codebase itself admits this at `internal/api/hosts.go:384`: *\"API trusts the bearer token for authorisation; per-CA ownership is enforced only in the Web layer.\"*\n\nThe Web UI gates state-changing routes through `loadAccessibleCA` (`internal/web/cas.go`); CA-management endpoints in `internal/api/cas.go` ALSO have proper `canAccessCA` gates. **The gap is on the host, network, firewall, mobile-bundle, and most operator endpoints.** Combined with the per-operator CA model from ADR 0002, this gives any non-admin operator API key broad cross-tenant access \u2014 instant privilege escalation in the worst case.\n\n## Affected\nAll released versions prior to v0.3.4.\n\n## Exploit chain\n\n### A) Mint admin API key from any operator key (instant privilege escalation)\n`internal/api/operators.go:118` \u2014 `handleCreateOperatorAPIKey` does no admin check and no actor/target-operator ownership check. Any operator key can call it for any operator (including admins) and receive a fresh bearer.\n\n```\ncurl -X POST -H \"Authorization: Bearer \u003clow-priv-key\u003e\" \\\n  https://server/api/v1/operators/\u003cadmin-id\u003e/api-keys \\\n  -H \u0027Content-Type: application/json\u0027 -d \u0027{\"name\":\"oops\"}\u0027\n# Returns: {\"key\":\"\u003c32-byte admin bearer\u003e\",\"entry\":{...}}\n```\n\nReuse the returned key for subsequent requests \u2192 full admin.\n\n### B) Cross-operator host takeover via reenroll\n`internal/api/hosts.go:321,330` \u2192 `mintEnrollmentTokenForHost`. Looks up host by URL param, mints a single-use enrollment token, returns it. No ownership check.\n\n```\ncurl -X POST -H \"Authorization: Bearer \u003clow-priv-key\u003e\" \\\n  https://server/api/v1/hosts/\u003cvictim-host-id\u003e/reenroll\n# Returns: {\"enrollment_token\":\"\u003cuuid\u003e\",...}\n```\n\nCaller POSTs `/api/v1/enroll` with their own X25519 + Ed25519 keypairs. `enroll.go:175` overwrites `signing_pub_pem`; `SaveCertificateAndEnrollHost` overwrites the cert. Legitimate agent\u0027s next signed poll fails `bad_signature`. Attacker now owns the victim\u0027s Nebula identity.\n\n### C) Cross-tenant CRUD on hosts, networks, firewall\nThe same gap applies across:\n- `/api/v1/hosts*` \u2014 create, list, get, update, delete, block, unblock\n- `/api/v1/networks*` \u2014 create, list, get\n- `/api/v1/networks/{id}/firewall` \u2014 get, PUT\n- `/api/v1/hosts/{id}/mobile-bundle` (already filed as public issue #119)\n\nAll trust bearer-auth alone. Any operator can read or mutate any other operator\u0027s resources.\n\n## Affected operator-management handlers (in addition to A)\nBeyond `handleCreateOperatorAPIKey` (covered by A), `internal/api/operators.go` is missing admin gates on:\n- `handleListOperators` (line 66) \u2014 operator roster info disclosure\n- `handleDisableOperator` (line 79) \u2014 DoS / sabotage\n- `handleEnableOperator` (line 94) \u2014 re-enable disabled operators\n- `handleRevokeOperatorAPIKey` (line 157) \u2014 invalidate any operator\u0027s API keys\n- `handleListOperatorAPIKeys` (line 173) \u2014 API-key metadata disclosure\n\n`handleCreateOperator` (line 26) IS properly gated (`actorIsAdmin` at line 27).\n\n## NOT affected (verified)\n`internal/api/cas.go` properly gates every CA endpoint via `canAccessCA` (calls at lines 70, 176, 216) and admin shortcuts at lines 39, 82. An earlier description draft mistakenly listed `/api/v1/cas/{id}/rotate` as affected \u2014 that endpoint is properly protected. CAs are not in this gap.\n\n## Impact\n- Any non-admin operator \u2192 admin via one curl (A).\n- Any non-admin operator \u2192 ownership of any victim\u0027s hosts with cert + identity transfer (B).\n- Mass cross-tenant CRUD including firewall-rule mutation (C).\n- Any operator \u2192 disable/enable other operators, revoke their API keys, enumerate the operator roster.\n\nCVSS 3.1: AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H \u2014 9.6.\n\n## Suggested fix\nShared helpers in a new `internal/api/authz.go`, mirroring the Web layer\u0027s `loadAccessibleCA`:\n\n```go\nfunc (s *Server) requireAdmin(w http.ResponseWriter, r *http.Request) bool\nfunc (s *Server) requireOperatorAccess(w http.ResponseWriter, r *http.Request, operatorID string) bool\nfunc (s *Server) requireHostAccess(w http.ResponseWriter, r *http.Request, hostID string) (*models.Host, bool)\nfunc (s *Server) requireNetworkAccess(w http.ResponseWriter, r *http.Request, networkID string) (*models.Network, bool)\n```\n\nEach loads the resource, resolves its CA via `*.CAID`, accepts if `actorIsAdmin(ctx)` OR actor owns the CA. Reject `403 forbidden`; audit-log `api.\u003cresource\u003e.forbidden` with the reason.\n\nThe operator-management endpoints take `requireAdmin` instead (operator ownership doesn\u0027t map to CA ownership).\n\nApply at the top of every host-, network-, firewall-, mobile-bundle-touching API handler, plus the 5 operator endpoints listed above. The legacy config-key path retains admin (preserves backward compatibility); the broader legacy-fallback question is tracked separately as issue #121.\n\n## Test matrix\n- admin \u2192 all operations permitted\n- owning non-admin \u2192 operations on owned hosts/networks permitted\n- non-owner non-admin \u2192 403 + audit entry\n- legacy config-key \u2192 preserved (admin)\n- unauthenticated \u2192 existing 401 from middleware\n\n## Coordinated context\nSubsumes public issue #119 (mobile-bundle authz). Issue #121 (actor.go:40 legacy-admin fallback) is a separate concern tracked independently.",
  "id": "GHSA-598g-h2vc-h5vg",
  "modified": "2026-06-08T23:09:02Z",
  "published": "2026-06-08T23:09:02Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/juev/nebula-mesh/security/advisories/GHSA-598g-h2vc-h5vg"
    },
    {
      "type": "WEB",
      "url": "https://github.com/forgekeep/nebula-mesh/commit/9d8bcd7667ecd0c2975cc71fb35a02fe131f76f2"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/juev/nebula-mesh"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H",
      "type": "CVSS_V3"
    }
  ],
  "summary": "nebula-mesh: API endpoints lack ownership checks, enabling cross-operator privilege escalation"
}

CVE-2026-47724 (GCVE-0-2026-47724)

Vulnerability from cvelistv5 – Published: 2026-07-23 20:20 – Updated: 2026-07-28 14:55

Title

nebula-mesh: API endpoints lack ownership checks, enabling cross-operator privilege escalation

Summary

nebula-mesh is a self-hosted control plane for Slack Nebula mesh virtual private network. Prior to version 0.3.4, the `/api/v1/*` route surface trusts the bearer token alone for authorisation on most endpoints. The codebase itself admits this at `internal/api/hosts.go:384`: "API trusts the bearer token for authorisation; per-CA ownership is enforced only in the Web layer." The Web UI gates state-changing routes through `loadAccessibleCA` (`internal/web/cas.go`); CA-management endpoints in `internal/api/cas.go` ALSO have proper `canAccessCA` gates. The gap is on the host, network, firewall, mobile-bundle, and most operator endpoints. Combined with the per-operator CA model from ADR 0002, this gives any non-admin operator API key broad cross-tenant access — instant privilege escalation in the worst case. Version 0.3.4 fixes the issue.

Severity

9.9 (Critical)


                        
                          CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H

SSVC

Exploitation: none Automatable: no Technical Impact: total

CISA Coordinator · CISA-ADP (v2.0.3)

Decision recorded 2026-07-28 14:29 UTC

CWE

CWE-862 - Missing Authorization

Assigner

GitHub_M mitre root

References

2 references

URL	Tags
https://github.com/forgekeep/nebula-mesh/security…	x_refsource_CONFIRM
https://github.com/forgekeep/nebula-mesh/commit/9…	x_refsource_MISC

Impacted products

1 product

Vendor	Product	Version
juev	nebula-mesh	Affected: < 0.3.4

Show details on NVD website

JSON

To clipboard

{
  "containers": {
    "adp": [
      {
        "metrics": [
          {
            "other": {
              "content": {
                "id": "CVE-2026-47724",
                "options": [
                  {
                    "Exploitation": "none"
                  },
                  {
                    "Automatable": "no"
                  },
                  {
                    "Technical Impact": "total"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-07-28T14:29:11.247252Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2026-07-28T14:55:31.612Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
        {
          "product": "nebula-mesh",
          "vendor": "juev",
          "versions": [
            {
              "status": "affected",
              "version": "\u003c 0.3.4"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "nebula-mesh is a self-hosted control plane for Slack Nebula mesh virtual private network. Prior to version 0.3.4, the `/api/v1/*` route surface trusts the bearer token alone for authorisation on most endpoints. The codebase itself admits this at `internal/api/hosts.go:384`: \"API trusts the bearer token for authorisation; per-CA ownership is enforced only in the Web layer.\" The Web UI gates state-changing routes through `loadAccessibleCA` (`internal/web/cas.go`); CA-management endpoints in `internal/api/cas.go` ALSO have proper `canAccessCA` gates. The gap is on the host, network, firewall, mobile-bundle, and most operator endpoints. Combined with the per-operator CA model from ADR 0002, this gives any non-admin operator API key broad cross-tenant access \u2014 instant privilege escalation in the worst case. Version 0.3.4 fixes the issue."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "attackComplexity": "LOW",
            "attackVector": "NETWORK",
            "availabilityImpact": "HIGH",
            "baseScore": 9.9,
            "baseSeverity": "CRITICAL",
            "confidentialityImpact": "HIGH",
            "integrityImpact": "HIGH",
            "privilegesRequired": "LOW",
            "scope": "CHANGED",
            "userInteraction": "NONE",
            "vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H",
            "version": "3.1"
          }
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-862",
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              "lang": "en",
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      ],
      "providerMetadata": {
        "dateUpdated": "2026-07-23T20:20:59.494Z",
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      },
      "references": [
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          "name": "https://github.com/forgekeep/nebula-mesh/security/advisories/GHSA-598g-h2vc-h5vg",
          "tags": [
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          ],
          "url": "https://github.com/forgekeep/nebula-mesh/security/advisories/GHSA-598g-h2vc-h5vg"
        },
        {
          "name": "https://github.com/forgekeep/nebula-mesh/commit/9d8bcd7667ecd0c2975cc71fb35a02fe131f76f2",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/forgekeep/nebula-mesh/commit/9d8bcd7667ecd0c2975cc71fb35a02fe131f76f2"
        }
      ],
      "source": {
        "advisory": "GHSA-598g-h2vc-h5vg",
        "discovery": "UNKNOWN"
      },
      "title": "nebula-mesh: API endpoints lack ownership checks, enabling cross-operator privilege escalation"
    }
  },
  "cveMetadata": {
    "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
    "assignerShortName": "GitHub_M",
    "cveId": "CVE-2026-47724",
    "datePublished": "2026-07-23T20:20:59.494Z",
    "dateReserved": "2026-05-19T21:29:25.482Z",
    "dateUpdated": "2026-07-28T14:55:31.612Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}

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.

Detection rules are retrieved from Rulezet.

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.
Browse all ATT&CK techniques and the vulnerabilities related to each.

Related by attack behaviour

Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.

Action not permitted

GHSA-598G-H2VC-H5VG

Affected

Exploit chain

A) Mint admin API key from any operator key (instant privilege escalation)

B) Cross-operator host takeover via reenroll

C) Cross-tenant CRUD on hosts, networks, firewall

Affected operator-management handlers (in addition to A)

NOT affected (verified)

Impact

Suggested fix

Test matrix

Coordinated context

CVE-2026-47724 (GCVE-0-2026-47724)

Tags

Sightings

Nomenclature

Related by attack behaviour