CVE-2021-23419Public exploitNetwork attack vector

Object prototype modification via unfiltered metadata keys

Published Aug 8, 2021 · Updated Sep 16, 2024

Prototype pollution in Sam Holmes Open Graph before 0.2.6 allows remote attackers to modify shared object properties via crafted metadata. The parse function splits attacker-controlled Open Graph property names into keys and follows proto or constructor paths into Object.prototype without rejecting them. The consuming Node.js application must fetch and parse attacker-controlled metadata; the resulting integrity impact depends on how later code uses inherited properties.

CVSS severity7.3
High
EPSS probability1.11%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

See if you're affected

Explore vulnerability checks for your environment with Hinoki.

Book a demo

Summary

What happened

Prototype pollution in Sam Holmes Open Graph before 0.2.6 allows remote attackers to modify shared object properties via crafted metadata. The parse function splits attacker-controlled Open Graph property names into keys and follows proto or constructor paths into Object.prototype without rejecting them. The consuming Node.js application must fetch and parse attacker-controlled metadata; the resulting integrity impact depends on how later code uses inherited properties.

The record

CVE
CVE-2021-23419
Published
Aug 8, 2021
Updated
Sep 16, 2024
Vendor
Sam Holmes
Product
Open Graph
Classifications
CWE-1321, CAPEC-180, CAPEC-1, CAPEC-77
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Aug 8, 2021CVE publishedPublication date reported by the CVE source.
  2. Sep 16, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

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

  1. Affected versionversion=unspecified <0.2.6

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Sam Holmes · Open Graphversion=unspecified <0.2.6

Published CVSS scores

9.8NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
5.3GitHubCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N
7.3Snyk CNACVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L
5.0NIST NVDAV:N/AC:L/Au:N/C:N/I:P/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
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-1321Improperly Controlled Modification of Object Prototype Attributes ('Prototype Pollution')
CAPEC-180Exploiting Incorrectly Configured Access Control Security Levels
CAPEC-1Accessing Functionality Not Properly Constrained by ACLs
CAPEC-77Manipulating User-Controlled Variables

Public exploit references

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

Technologies

Your stack

See the directory against your own environment.

Your stack

Check the software in your environment

Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.

Book a demo