Security Digest · Vulnerability record
CVE-2026-70478: Flowise: Unauthenticated OAuth2 token refresh endpoint returns access tokens — enables token theft for any connected service
Flowise is a drag & drop user interface to build a customized large language model flow.
CVSS 9.2 Critical EPSS 0.6% · p49
Should you act?
Critical and remotely reachable
No known exploitation yet, but it is network-reachable without credentials. This signal is computed from CISA KEV, EPSS and CVSS data; it is not an editorial verdict.
- Not in CISA KEV, but CISA’s SSVC assessment records a public proof-of-concept, so attack code exists.
- EPSS 0.6%, percentile 49: FIRST’s model estimates a 0.6% chance of exploitation activity in the next 30 days, higher than 49% of all scored CVEs (low). EPSS is a probability, not a verdict.
- Remotely reachable with no login and no user interaction. If the vulnerable service is exposed to the internet, prioritize it.
- Only applies if your dependency tree includes
flowise(npm) <= 3.1.2, fixed in 3.1.3. Check your lockfile, including transitive dependencies.
What it is
Flowise is a drag & drop user interface to build a customized large language model flow. Prior to 3.1.3, the POST /api/v1/oauth2-credential/refresh/:credentialId endpoint is included in WHITELISTURLS and requires no authentication. The endpoint decrypts the stored credential, sends a refresh request to the configured OAuth provider with the client secret and refresh token, and returns the refreshed accesstoken in the response body. An attacker with a credential ID can use the token to access the victim's connected service and can also exhaust refresh-token quota. This issue is fixed in 3.1.3.
From the GitHub advisory
Summary
The OAuth2 token refresh endpoint (POST /api/v1/oauth2-credential/refresh/:credentialId) is in WHITELISTURLS, meaning it requires no authentication. It decrypts the stored credential (containing clientId, clientSecret, refreshtoken), sends a refresh request to the configured OAuth provider, and returns the new accesstoken directly in the response body.
Root Cause
Whitelist entry at packages/server/src/utils/constants.ts:40.
Attack Chain
Weakness type: CWE-200.
Product: flowise (npm) · Assigned by: GitHub_M · Published: 2026-08-04
Affected and fixed versions
| Ecosystem | Package | Vulnerable | First fixed |
|---|---|---|---|
| npm | flowise | <= 3.1.2 | 3.1.3 |
| Vendor | Product | Affected versions (per CVE record) |
|---|---|---|
| FlowiseAI | Flowise | < 3.1.2 |
Severity scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| GitHub_M | 4.0 | 9.2 Critical | CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:L/VA:N/SC:H/SI:L/SA:N |
| GitHub | 4.0 | 9.2 | CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:L/VA:N/SC:H/SI:L/SA:N |
- Attack vector: network (remotely reachable)
- Attack complexity: low
- Attack requirements: none
- Privileges required: none (no login)
- User interaction: none
CVSS measures how bad a flaw is if exploited, not how likely exploitation is. Read it next to the exploitation data below.
Exploitation and urgency
- CISA KEV: not listed (no confirmed in-the-wild exploitation known to CISA).
- CISA SSVC assessment: exploitation poc, automatable yes, technical impact partial.
- FIRST EPSS (model of 2026-10-21): 0.61% probability of exploitation activity in the next 30 days; percentile 49.
Timeline
- — CVE record published by GitHub_M
- — GitHub-reviewed advisory GHSA-qgvm-j2hm-6m38 published (critical)
- — CVE record last updated
Sources and references
Original sources first. Version and fix details should always be confirmed against the vendor or project advisory.
Vulnerability records
- GitHub Advisory GHSA-qgvm-j2hm-6m38 github.com
- CVE.org record CVE-2026-70478 cve.org
- NVD entry CVE-2026-70478 nvd.nist.gov
Other references from the CVE record and advisory
- github.com github.com