Flowise: CVE-2025-8943 Patch Bypass: npm_config_yes bypasses MCP environment variable blocklist (Unauthenticated RCE)

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS 4.0

8.7 · CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N · score source

EPSS

• CVE-2026-69263: 0.66% estimated exploitation activity in the next 30 days; percentile 51.71 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

Summary The mitigation shipped for CVE-2025-8943 blocks the -y and --yes flags on npx to stop auto-installation of arbitrary packages. That flag filter works. The environment-variable check in the same patch denies only four variable names by exact string match, and npm reads its configuration directly from npmconfig environment variables. Setting npmconfigyes=true reproduces the --yes behaviour the flag filter is meant to prevent, so npx auto-installs and executes the named package. The mitigation is fully bypassed. This works with the MCP security check enabled (CUSTOMMCPSECURITYCHECK=true). On a default Flowise deployment, which ships with no authentication, the result is unauthenticated remote code execution. Root cause The patch treats this as a flag-filtering problem, but the behaviour gated by --yes is also reachable through npm's environment-based configuration. The same is true for the other permitted interpreters, node and python3. A denylist of variable names cannot…

Published by the source

4 Aug 2026, 17:09 UTC

Last modified by the source

4 Aug 2026, 17:09 UTC

Source last checked

26 Oct 2026, 13:00 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-xc48-889x-5qmw

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# Patch Next advisory brief: CVE-2026-69263

Advisory: Flowise: CVE-2025-8943 Patch Bypass: npm_config_yes bypasses MCP environment variable blocklist (Unauthenticated RCE)
IDs: CVE-2026-69263, GHSA-xc48-889x-5qmw
Record: https://patchnext.com/advisories/cve-2026-69263 (revision 1, source checked 26 Oct 2026, 13:00 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: High (CVSS 8.7)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: flowise-components 3.1.3; flowise 3.1.3. A vendor fix does not mean a deployment is fixed.

## Affected components
- npm flowise-components: affected <= 3.1.2; fixed in 3.1.3
- npm flowise: affected <= 3.1.2; fixed in 3.1.3

## Suggested inspection (read-only)
- `npm ls flowise-components --all`: lists every installed copy and version, including transitive ones. Run in the project root after `npm ci`.
- `npm ls flowise --all`: lists every installed copy and version, including transitive ones. Run in the project root after `npm ci`.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on flowise-components, flowise.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://github.com/advisories/GHSA-xc48-889x-5qmw (GitHub-reviewed advisory GHSA-xc48-889x-5qmw lists affected ranges: npm flowise >=0 =0 <=3.1.2)

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