web3-core-method is vulnerable to prototype pollution

published 2025-09-24 13 mo ago modified 2026-06-17 4 mo ago also GHSA-2j4c-9qqq-896r , EUVD-2025-31063

cvss: 7.5; version 3.1, CNA
cisa kev: Not listed; not in CISA's catalog
epss: 0.4%; EPSS 0.4% chance of exploitation in 30 days, percentile 33%
public exploits: 0; none known

web3-core-method is a package designed to creates the methods on the web3 modules. A Prototype Pollution vulnerability in the attachToObject function of web3-core-method version 1.10.4 and before allows attackers to inject properties on Object.prototype via supplying a crafted payload, causing denial of service (DoS) as the minimum consequence.

CISA SSVC

Exploitation: none
Automatable: yes
Technical impact: partial
Assessed: 13 mo ago (2025-09-26)

Exploit prediction

0.39% chance of exploitation in the next 30 days, higher than 33% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by	version	score	vector
CISA ADP	3.1	7.5	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
CNA	3.1	7.5	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Affected packages

ecosystem	package	affected	fixed in
npm	web3-core-method	<=1.10.3	no fix listed

Classification

Weakness

CWE-1321 Improperly Controlled Modification of Object Prototype Attributes

References

github.com /VulnSageAgent/PoCs/blob/main/JavaScript/prototype-pollution/web3-core-method%401.10.4/index.js
web, broken-link
github.com /VulnSageAgent/PoCs/tree/main/JavaScript/prototype-pollution/CVE-2025-57329
web, third-party-advisory
nvd.nist.gov /vuln/detail/CVE-2025-57329
advisory
github.com /web3/web3.js/tree/1.x
package

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

Summary