Vulnerability in Flowise
CVE-2026-56277
Flowise before 3.1.2 sets Access-Control-Allow-Origin to a hardcoded wildcard (*) on its text-to-speech (TTS) generation endpoint (packages/server/src/controllers/text-to-speech/index.ts), independent of the server's configured CORS policy. This bypasses the server's otherwise restrictive default CORS configuration (getCorsOptions()) and allows any webpage to make cross-origin requests that trigger TTS generation using stored credentials, enabling drive-by cross-origin credential abuse.
Published · last modified .
CVSS v3 metric
CVSS v3 base score 6.5 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N.
EPSS exploit prediction
EPSS: 0.002 (6.7th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 7th percentile — 6.7% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.002 · newest: 0.002 · change: 0.000
Affected products
- Flowise — versions 0, 3.1.2
- Flowiseai Flowise
Weakness classification (CWE)
References
- github.com/FlowiseAI/Flowise/security/advisories/GHSA-m837-xvxr-vqwg (vendor-advisory, Mitigation, Vendor Advisory)
- www.vulncheck.com/advisories/flowise-hardcoded-cors-wildcard-in-tts-endpoint (Third Party Advisory, third-party-advisory)
Frequently asked questions
- What is CVE-2026-56277?
- CVE-2026-56277 is a medium-severity vulnerability in Flowise, classified under Origin Validation Error. CVSS score: 6.5/10. Published 2026-06-30.
- How severe is CVE-2026-56277?
- Medium severity. CVSS v3 base score is 6.5 out of 10.