CVE-2021-25946Network attack vector

Process crash or code execution via prototype pollution

Published May 25, 2021 · Updated Aug 3, 2024

Prototype pollution in Rob Loach nconf-toml 0.0.1 through 0.0.2 allows attackers to corrupt the Node.js object prototype via crafted TOML input. The package exports its toml dependency's parse function directly, so attacker-controlled special property keys reach the dependency without filtering by the plugin. Exploitation requires a consuming application to parse attacker-controlled TOML; a polluted prototype can crash the process, while code execution depends on a compatible application gadget.

CVSS severity9.8
Critical
EPSS probability3.30%
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 Rob Loach nconf-toml 0.0.1 through 0.0.2 allows attackers to corrupt the Node.js object prototype via crafted TOML input. The package exports its toml dependency's parse function directly, so attacker-controlled special property keys reach the dependency without filtering by the plugin. Exploitation requires a consuming application to parse attacker-controlled TOML; a polluted prototype can crash the process, while code execution depends on a compatible application gadget.

The record

CVE
CVE-2021-25946
Published
May 25, 2021
Updated
Aug 3, 2024
Vendor
Rob Loach
Product
nconf-toml
Classifications
CWE-1321
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. May 25, 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=0.0.1,0.0.2

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Rob Loach · nconf-tomlversion=0.0.1,0.0.2

Published CVSS scores

7.5NIST NVDAV:N/AC:L/Au:N/C:P/I:P/A:P
9.8NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

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 exploitUnconfirmed

Weakness, pattern, technique

CWE-1321Improperly Controlled Modification of Object Prototype Attributes ('Prototype Pollution')

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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