CVE-2021-21297Network attack vector

Runtime behavior modification via prototype pollution

Published Feb 26, 2021 · Updated Aug 3, 2024

Prototype pollution in the Node-RED Admin API before 1.2.8 allows remote attackers with editor access to alter runtime behavior via malformed requests. The affected request processing accepts a malformed object structure and writes attacker-controlled properties into the default JavaScript Object prototype. Access requires reachability to the editor URL and any configured Admin API authorization; the documented impact is runtime-behavior modification, not data disclosure or service interruption.

CVSS severity7.7
High
EPSS probability1.40%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Prototype pollution in the Node-RED Admin API before 1.2.8 allows remote attackers with editor access to alter runtime behavior via malformed requests. The affected request processing accepts a malformed object structure and writes attacker-controlled properties into the default JavaScript Object prototype. Access requires reachability to the editor URL and any configured Admin API authorization; the documented impact is runtime-behavior modification, not data disclosure or service interruption.

The record

CVE
CVE-2021-21297
Published
Feb 26, 2021
Updated
Aug 3, 2024
Vendor
Node-RED
Product
Node-RED
Classifications
CWE-915, CWE-1321, T1190
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Feb 26, 2021CVE publishedPublication date reported by the CVE source.
  2. Aug 3, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=< 1.2.8

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Node-RED · Node-REDversion=< 1.2.8

Published CVSS scores

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

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-915Improperly Controlled Modification of Dynamically-Determined Object Attributes
CWE-1321Improperly Controlled Modification of Object Prototype Attributes ('Prototype Pollution')
T1190Exploit Public-Facing Application

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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