Flowise: Authenticated arbitrary file write in the S3 Directory document loader via unsanitized S3 object keys

Exploitation

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

CVSS 4.0

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

EPSS

No dated EPSS signal available.

As published by the source; long descriptions are shortened.

Summary Flowise on current main allows an authenticated user with documentStores:preview-process permission to trigger the S3 Directory document loader with attacker-controlled S3 object keys. The loader joins each returned S3 key with a temporary directory using path.join(tempDir, key) and writes the object bytes to disk without validating traversal sequences such as ../. Cleanup later removes only the original temporary directory, so files written outside that directory persist on the host filesystem. This yields arbitrary file write with the privileges of the Flowise server process. A related variant exists in the S3File loader when fileProcessingMethod = unstructured (same root cause; its cleanup behavior turns it into a mixed arbitrary write/delete/DoS primitive).

Affected component - packages/components/nodes/documentloaders/S3Directory/S3Directory.ts - line 191: filePath = path.join(tempDir, key) (unsanitized) - line 213: recursive mkdirSync creates parent path - line 216:…

Published by the source

4 Aug 2026, 17:43 UTC

Last modified by the source

4 Aug 2026, 17:43 UTC

Source last checked

26 Oct 2026, 13:00 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-88pr-878c-24wf

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# Patch Next advisory brief: GHSA-88pr-878c-24wf

Advisory: Flowise: Authenticated arbitrary file write in the `S3 Directory` document loader via unsanitized S3 object keys
IDs: GHSA-88pr-878c-24wf
Record: https://patchnext.com/advisories/ghsa-88pr-878c-24wf (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 7.2)
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-88pr-878c-24wf (GitHub-reviewed advisory GHSA-88pr-878c-24wf lists affected ranges: npm flowise-components >=0 =0 <=3.1.2)

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