# CVE-2026-56277: Flowise - Hardcoded CORS Wildcard in TTS Endpoint

> Attackers can bypass CORS restrictions to trigger TTS generation using stored credentials via cross-origin requests.

- **Severity:** Medium 6.9 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 30 Jun 2026
- **Updated:** 1 Jul 2026
- **Also known as:** GHSA-8m62-6r3h-3x25, GHSA-m837-xvxr-vqwg

## What is CVE-2026-56277?

CVE-2026-56277 is a medium-severity vulnerability in Flowiseai Flowise, published on 30 Jun 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official 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.

Weakness: CWE-346 (Origin Validation Error)

## Which versions are affected by CVE-2026-56277?

2 open source packages ship an affected version, including flowise. It affects 1 product.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `flowise` | npm | All versions | 3.1.2 |
| `flowise` | npm | All versions | 3.1.2 |

Products: Flowiseai Flowise.

## How do I fix CVE-2026-56277?

Upgrade flowise to 3.1.2 or later.

## Is CVE-2026-56277 being exploited?

There is no known exploitation of CVE-2026-56277 in the wild and no public exploit code.

## Other vulnerabilities in Flowiseai Flowise

- [CVE-2025-71338](https://insights.sbomify.com/CVE-2025-71338/): Flowise through 2.2.7 - Arbitrary File Write to Remote Code Execution via document-store API (critical 10.0)
- [CVE-2026-40933](https://insights.sbomify.com/CVE-2026-40933/): Flowise: Authenticated RCE Via MCP Adapters (critical 10.0)
- [CVE-2025-61913](https://insights.sbomify.com/CVE-2025-61913/): Flowise is vulnerable to arbitrary file read, arbitrary file write (critical 10.0)
- [CVE-2025-59528](https://insights.sbomify.com/CVE-2025-59528/): Flowise has Remote Code Execution vulnerability (critical 10.0)
- [CVE-2026-52098](https://insights.sbomify.com/CVE-2026-52098/): Code injection in n/a (critical 9.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-56277 and fix it if it is affected.

What it is: CVE-2026-56277 is a medium-severity vulnerability in Flowiseai Flowise, published on 30 Jun 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-56277 in the wild and no public exploit code.

Affected packages and fixed versions:
- flowise (npm): affected all versions; fixed in 3.1.2
- flowise (npm): affected all versions; fixed in 3.1.2

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-56277/ (Markdown: https://insights.sbomify.com/CVE-2026-56277/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-56277
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-56277
- OSV: https://osv.dev/vulnerability/CVE-2026-56277

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-56277/
Summaries are generated and may contain mistakes; the official description above is the record.