Medium severity · published Jun 30, 2026
CVE-2026-56277
Flowise - Hardcoded CORS Wildcard in TTS Endpoint
6.5
CVSS
0.2%
EPSS
No
On KEV
Description
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.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Confidentiality
Low
Integrity
Low
Availability
None
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.2% · higher than 7% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
FL
Flowise · Flowise
before 3.1.2 · source: vendor, NVD
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-56277
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-56277
Mitigation
https://github.com/FlowiseAI/Flowise/security/advisories/GHSA-m837-xvxr-vqwg
Third Party Advisory
https://www.vulncheck.com/advisories/flowise-hardcoded-cors-wildcard-in-tts-endpoint
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