What is CVE-2025-57323?

CVE-2025-57323 is a high-severity vulnerability in Regularjs Mpregular, classified under Improperly Controlled Modification of Object Prototype Attributes (Prototype Pollution). CVSS score: 7.5/10. Published 2025-09-24.

How severe is CVE-2025-57323?

High severity. CVSS v3 base score is 7.5 out of 10.

Prototype Pollution in Regularjs Mpregular

CVE-2025-57323

mpregular is a package that provides a small program development framework based on RegularJS. A Prototype Pollution vulnerability in the mp.addEventHandler function of mpregular version 0.2.0 and before allows attackers to inject properties on Object.prototype via supplying a crafted payload, causing denial of service (DoS) as the minimum consequence.

Vulnerability class: Prototype Pollution

EPSS: 0.004 (31.3th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.

Affected products

Regularjs Mpregular
N/a — versions n/a

Weakness classification (CWE)

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

References

cve@mitre.org (Broken Link)
cve@mitre.org (Third Party Advisory)

Frequently asked questions

What is CVE-2025-57323?: CVE-2025-57323 is a high-severity vulnerability in Regularjs Mpregular, classified under Improperly Controlled Modification of Object Prototype Attributes (Prototype Pollution). CVSS score: 7.5/10. Published 2025-09-24.
How severe is CVE-2025-57323?: High severity. CVSS v3 base score is 7.5 out of 10.