CVE-2021-25943

CRITICALNVD 9.89.8—

9.8

Prototype pollution vulnerability in '101' versions 1.0.0 through 1.6.3 allows an attacker to cause a denial of service and may lead to remote code execution.

CVSS v3: 9.8
EG Score: 9.8(medium)
EPSS: 86.6%
KEV: Not listed

Published

May 14, 2021

Last Modified

April 30, 2025

References (4)

vulnerabilitylab@mendhttps://github.com/tjmehta/101/blob/d87f63ce2a4cbdc476e8287abd78327c3144d646/set.js#L52
vulnerabilitylab@mendhttps://www.whitesourcesoftware.com/vulnerability-database/CVE-2021-25943
af854a3a-2127-422b-91ae-364da2661108https://github.com/tjmehta/101/blob/d87f63ce2a4cbdc476e8287abd78327c3144d646/set.js#L52
af854a3a-2127-422b-91ae-364da2661108https://www.whitesourcesoftware.com/vulnerability-database/CVE-2021-25943

Patch Availability(1)

Vendor / Ecosystem	Fixed in / Patch	Released	Source
npm	101	—	ghsa

Patches are aggregated from vendor advisories (Red Hat, Microsoft, Cisco, GitHub) and package ecosystems (OSV, GHSA). Multiple rows for the same upstream release have been deduplicated.

Affected Packages

(1 across 1 ecosystem)

npm(1)

Package	Vulnerable range	Fixed in	Dependents
101	—	—	—

Weakness Classification(1)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

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

Data Freshness Timeline

(refreshed 7× in last 7d / 7× in last 30d)

Every time one of our enrichment pipelines (NVD, MITRE cvelistV5, EPSS, CISA KEV, GHSA, OSV, vendor advisories) ran against this CVE. Most recent first.

2026-05-27 13:39 UTCepss_batch
2026-05-27 13:39 UTCepss_batch
2026-05-26 16:36 UTCEG score recompute
2026-05-26 16:36 UTCGHSA enrichment
2026-05-26 13:42 UTCepss_batch
2026-05-26 07:17 UTCepss_batch
2026-05-26 07:17 UTCepss_batch

Frequently asked(5)

What is CVE-2021-25943?

CVE-2021-25943 is a critical vulnerability published on May 14, 2021. Prototype pollution vulnerability in '101' versions 1.0.0 through 1.6.3 allows an attacker to cause a denial of service and may lead to remote code execution.

When was CVE-2021-25943 disclosed?

CVE-2021-25943 was first published in the National Vulnerability Database on May 14, 2021, with the most recent update on April 30, 2025. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.

Is CVE-2021-25943 actively exploited?

CVE-2021-25943 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 86.6% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.

What is the CVSS score of CVE-2021-25943?

CVE-2021-25943 has a CVSS v3 base score of 9.8 (NVD).

How do I remediate CVE-2021-25943?

Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2021-25943, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

Dependency Blast Radius

See which npm, PyPI, Go, and Maven packages are affected by CVE-2021-25943

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