Arcane: Delegated users:update permission allows admin account takeover via password reset (no privilege-hierarchy check)

{
  "id": "21ff4d9b9c94ec51c1a53a18290e5d42b527458d7c4ece730391f13e7ee951f5",
  "url": "https://osv.dev/vulnerability/GHSA-pw5q-rjx4-7f7p",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "Arcane: Delegated users:update permission allows admin account takeover via password reset (no privilege-hierarchy check)",
    "summary": "## Summary A user holding the delegated `users:update` permission can reset the global administrator's password and take over the admin account. `UpdateUser` sets the target user's `PasswordHash` from the request body for ANY target with no comparison of caller-vs-target privilege. Because role assignment and role CRUD are deliberately gated by `RequireGlobalAdmin`, `users:update` is intended to sit BELOW admin (profile management); this finding defeats that separation. ## Root Cause `UpdateUser` (handler `backend/api/handlers/users.go:317-323`) loads the target by ID and sets `userModel.PasswordHash` from the request body for any user, then `userService.UpdateUser` (`user_service.go:174`) simply `tx.Save`s — with NO actor-vs-target privilege comparison. The only `IsGlobalAdmin` guard (`user_service.go:345`) is a last-admin check inside `DeleteUser`, not the update path. Role assignment / role CRUD are `RequireGlobalAdmin` (`backend/pkg/authz/permissions.go:27-33`), proving `users:update` is intended below admin. ## Impact Complete administrator account takeover (C:H/I:H/A:H) by any holder of the delegated `users:update` permission. ## Proof of Concept 1. Admin delegates a custom \"User Manager\" role with `users:update`. 2. `PUT /users/{adminId}` with `{\"password\":\"attacker123\"}`. 3. `POST /auth/login {\"username\":\"arcane\",\"password\":\"attacker123\"}` → admin session. ## Attack Chain 1. Action: admin delegates custom role with `users:update`. Guard: role creation is `RequireGloba",
    "evidence": "osv:GHSA-pw5q-rjx4-7f7p",
    "products": [
      {
        "name": {
          "value": "github.com/getarcaneapp/arcane/backend/v2",
          "evidence": "/affected/0/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [
          {
            "value": "2.6.0",
            "evidence": "/affected/0/ranges"
          }
        ],
        "affected_versions": []
      }
    ],
    "severity": "high",
    "structured": {
      "id": "GHSA-pw5q-rjx4-7f7p",
      "aliases": [
        "CVE-2026-96627",
        "GHSA-pw5q-rjx4-7f7p",
        "GO-2026-6807"
      ],
      "metrics": [
        {
          "type": "CVSS_V3",
          "score": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "type": "SEMVER",
              "events": [
                {
                  "introduced": "0"
                },
                {
                  "fixed": "2.6.0"
                }
              ]
            }
          ],
          "package": {
            "name": "github.com/getarcaneapp/arcane/backend/v2",
            "purl": "pkg:golang/github.com/getarcaneapp/arcane/backend/v2",
            "ecosystem": "Go"
          },
          "database_specific": {
            "source": "https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/10/GHSA-pw5q-rjx4-7f7p/GHSA-pw5q-rjx4-7f7p.json"
          }
        }
      ],
      "modified": "2026-10-19T21:40:44.932520248Z",
      "provider": "osv",
      "references": [
        "https://github.com/getarcaneapp/arcane/security/advisories/GHSA-pw5q-rjx4-7f7p",
        "https://github.com/getarcaneapp/arcane/pull/3426",
        "https://github.com/getarcaneapp/arcane/commit/21ea962f86d967dac8ae02a050f6e5f043d10fa1",
        "https://github.com/getarcaneapp/arcane",
        "https://github.com/getarcaneapp/arcane/releases/tag/backend/v2.6.0"
      ],
      "provider_metadata": {
        "cwe_ids": [
          "CWE-266",
          "CWE-269"
        ],
        "severity": "HIGH",
        "github_reviewed": true,
        "nvd_published_at": null,
        "github_reviewed_at": "2026-10-16T21:15:03Z"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-96627",
        "evidence": "/aliases"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/database_specific/severity"
  },
  "source_id": "core-osv",
  "document_id": 376733,
  "published_at": "2026-10-16T21:15:03+00:00"
}

{
  "id": "7a62d29d84dc400c36ae8a96ba29fbb2b84e386a9d2fb10f6d588b886617554f",
  "url": "https://osv.dev/vulnerability/GO-2026-6807",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "Arcane: Delegated users:update permission allows admin account takeover via password reset (no privilege-hierarchy check) in github.com/getarcaneapp/arcane/backend",
    "summary": "Arcane: Delegated users:update permission allows admin account takeover via password reset (no privilege-hierarchy check) in github.com/getarcaneapp/arcane/backend",
    "evidence": "osv:GO-2026-6807",
    "products": [
      {
        "name": {
          "value": "github.com/getarcaneapp/arcane/backend",
          "evidence": "/affected/0/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [],
        "affected_versions": []
      },
      {
        "name": {
          "value": "github.com/getarcaneapp/arcane/backend/v2",
          "evidence": "/affected/1/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [
          {
            "value": "2.6.0",
            "evidence": "/affected/1/ranges"
          }
        ],
        "affected_versions": []
      }
    ],
    "severity": "unknown",
    "structured": {
      "id": "GO-2026-6807",
      "aliases": [
        "CVE-2026-96627",
        "GHSA-pw5q-rjx4-7f7p",
        "GO-2026-6807"
      ],
      "affected": [
        {
          "ranges": [
            {
              "type": "SEMVER",
              "events": [
                {
                  "introduced": "0"
                }
              ]
            }
          ],
          "package": {
            "name": "github.com/getarcaneapp/arcane/backend",
            "purl": "pkg:golang/github.com/getarcaneapp/arcane/backend",
            "ecosystem": "Go"
          },
          "database_specific": {
            "source": "https://vuln.go.dev/ID/GO-2026-6807.json"
          },
          "ecosystem_specific": {}
        },
        {
          "ranges": [
            {
              "type": "SEMVER",
              "events": [
                {
                  "introduced": "0"
                },
                {
                  "fixed": "2.6.0"
                }
              ]
            }
          ],
          "package": {
            "name": "github.com/getarcaneapp/arcane/backend/v2",
            "purl": "pkg:golang/github.com/getarcaneapp/arcane/backend/v2",
            "ecosystem": "Go"
          },
          "database_specific": {
            "source": "https://vuln.go.dev/ID/GO-2026-6807.json"
          },
          "ecosystem_specific": {}
        }
      ],
      "modified": "2026-10-19T21:31:38.407415618Z",
      "provider": "osv",
      "references": [
        "https://github.com/getarcaneapp/arcane/security/advisories/GHSA-pw5q-rjx4-7f7p",
        "https://github.com/getarcaneapp/arcane/commit/21ea962f86d967dac8ae02a050f6e5f043d10fa1",
        "https://github.com/getarcaneapp/arcane/pull/3426",
        "https://github.com/getarcaneapp/arcane/releases/tag/backend/v2.6.0"
      ],
      "provider_metadata": {
        "url": "https://pkg.go.dev/vuln/GO-2026-6807",
        "review_status": "UNREVIEWED"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-96627",
        "evidence": "/aliases"
      }
    ],
    "security_relevant": true,
    "severity_evidence": null
  },
  "source_id": "core-osv",
  "document_id": 376575,
  "published_at": "2026-10-19T21:08:35+00:00"
}