What is CVE-2023-26133?

CVE-2023-26133 is a high-severity vulnerability in Progressbar.js Project, classified under Improperly Controlled Modification of Object Prototype Attributes (Prototype Pollution). CVSS score: 8.2/10. Published 2023-06-12.

How severe is CVE-2023-26133?

High severity. CVSS v3 base score is 8.2 out of 10.

Prototype Pollution in Progressbar.js Project

CVE-2023-26133

All versions of the package progressbar.js are vulnerable to Prototype Pollution via the function extend() in the file utils.js.

Vulnerability class: Prototype Pollution

Published 2023-06-12 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 8.2 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:L.

EPSS exploit prediction

EPSS: 0.013 (69.4th percentile), scored 2026-10-24.

Low probability of exploitation in the next 30 days, but still tracked. 69th percentile — 69.4% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.013 · newest: 0.013 · change: +0.000

Affected products

Progressbar.js Project
Progressbar.js — versions 0

Weakness classification (CWE)

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

References

security.snyk.io/vuln/SNYK-JS-PROGRESSBARJS-3184152 (Exploit, Third Party Advisory)
github.com/kimmobrunfeldt/progressbar.js/blob/74536b9eeeaaf51144706d918ed5a0a67… (Broken Link)
github.com/kimmobrunfeldt/progressbar.js/blob/74536b9eeeaaf51144706d918ed5a0a67… (Broken Link)

Frequently asked questions

What is CVE-2023-26133?: CVE-2023-26133 is a high-severity vulnerability in Progressbar.js Project, classified under Improperly Controlled Modification of Object Prototype Attributes (Prototype Pollution). CVSS score: 8.2/10. Published 2023-06-12.
How severe is CVE-2023-26133?: High severity. CVSS v3 base score is 8.2 out of 10.