Prototype Pollution in Node-Red

Exploitation

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

CVSS

7.7 · CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:N/I:H/A:N

EPSS

• CVE-2021-21297: 1.40% estimated exploitation activity in the next 30 days; percentile 72.46 (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.

Impact Node-RED 1.2.7 and earlier contains a Prototype Pollution vulnerability in the admin API. A badly formed request can modify the prototype of the default JavaScript Object with the potential to affect the default behaviour of the Node-RED runtime. Patches The vulnerability is patched in the 1.2.8 release. Workarounds A workaround is to ensure only authorised users are able to access the editor url. For more information If you have any questions or comments about this advisory: Email us at team@nodered.org Acknowledgements Thanks to the Tencent Woodpecker Security Team for disclosing this vulnerability.

Published by the source

26 Feb 2021, 16:31 UTC

Last modified by the source

8 Jul 2026, 06:28 UTC

Source last checked

26 Oct 2026, 12:20 UTC

1. Revision 2 · amended · 26 Oct 2026

   Amended from ghsa record GHSA-xp9c-82x8-7f67

2. Revision 1 · created · 24 Oct 2026

   Published from osv record GHSA-xp9c-82x8-7f67

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# Patch Next advisory brief: CVE-2021-21297

Advisory: Prototype Pollution in Node-Red
IDs: CVE-2021-21297, GHSA-xp9c-82x8-7f67
Record: https://patchnext.com/advisories/cve-2021-21297 (revision 2, source checked 26 Oct 2026, 12:20 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: High (CVSS 7.7)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: @node-red/runtime 1.2.8. A vendor fix does not mean a deployment is fixed.

## Affected components
- npm @node-red/runtime: affected < 1.2.8; fixed in 1.2.8

## Suggested inspection (read-only)
- `npm ls @node-red/runtime --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 @node-red/runtime.
- 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://osv.dev/vulnerability/GHSA-xp9c-82x8-7f67 (OSV record GHSA-xp9c-82x8-7f67 lists affected ranges: npm @node-red/runtime >=0 <1.2.8 (fixed))
- Verified: https://github.com/advisories/GHSA-xp9c-82x8-7f67 (GitHub-reviewed advisory GHSA-xp9c-82x8-7f67 lists affected ranges: npm @node-red/runtime >=0 <1.2.8)

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