vulnerability / NVI-00015413 / Revision 1
Flowise: CVE-2025-8943 Patch Bypass: npm_config_yes bypasses MCP environment variable blocklist (Unauthenticated RCE)
GitHub lists this reviewed advisory for flowise, flowise-components. Published version ranges and source prerequisites are shown below; this is not an inspection of a visitor’s application.
This report has not inspected your inventory, configuration, deployed build, reachability or evidence. A catalog listing and a severity score do not establish exposure or compromise.
01 / Meaning
Why it matters
Published affected context helps an owner decide what evidence to gather. This report has not examined your application.
02 / Applicability
The affected context
Affected versions, configuration prerequisites and known exclusions are public. Confirm each one against the deployed service.
flowise
source listed<= 3.1.2
## 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 `npm_config_*` environment variables. Setting `npm_config_yes=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 (`CUSTOM_MCP_SECURITY_CHECK=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 enumerate every environment variable that alters execution, so the control is incomplete by construction. The fix is to allowlist (or strip) the environment before
flowise-components
source listed<= 3.1.2
## 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 `npm_config_*` environment variables. Setting `npm_config_yes=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 (`CUSTOM_MCP_SECURITY_CHECK=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 enumerate every environment variable that alters execution, so the control is incomplete by construction. The fix is to allowlist (or strip) the environment before
03 / Response
What to do next
- investigate
Identify the exact component and deployed version, examine the linked publisher’s conditions, and retain evidence of any mitigation.
Confirm current vendor support, compatibility and deployment evidence. This report has not tested a fix in your system. GitHub Advisory Database
A fixed release is not deployment evidence.
Check current vendor support and compatibility. After making a change, verify the deployed build and relevant runtime conditions. Keep the evidence, owner and time. An updated lockfile alone does not prove what is running.
04 / Limits
What this report cannot establish
- Customer inventory, deployment, reachability and exploitation have not been inspected.
05 / Provenance
Sources you can inspect
Each assertion retains its source. Mirrored records may repeat one underlying publisher; additional links are not independent corroboration.
- GHSA-xc48-889x-5qmw ↗
GitHub Advisory Database · vendor advisory
Observed . GitHub Advisory Database; CC-BY-4.0. Each advisory links its original attribution. Null normalizes fields.
Public revision history
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- Revision 1 ·
First indexed by Null; source disclosure date is shown separately.