What is CVE-2021-41097?

CVE-2021-41097 is a critical-severity vulnerability in Aurelia Path, classified under Improperly Controlled Modification of Object Prototype Attributes (Prototype Pollution). CVSS score: 9.1/10. Published 2021-09-27.

How severe is CVE-2021-41097?

Critical severity. CVSS v3 base score is 9.1 out of 10.

Prototype Pollution in Aurelia Path

CVE-2021-41097

aurelia-path is part of the Aurelia platform and contains utilities for path manipulation. There is a prototype pollution vulnerability in aurelia-path before version 1.1.7. The vulnerability exposes Aurelia application that uses `aurelia-path` package to parse a string. The majority of this will be Aurelia applications that employ the `aurelia-router` package. An example is this could allow an attacker to change the prototype of base object class `Object` by tricking an application to parse the following URL: `https://aurelia.io/blog/?__proto__[asdf]=asdf`. The problem is patched in version `1.1.7`.

Vulnerability class: Prototype Pollution

Published 2021-09-27 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 9.1 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N.

EPSS exploit prediction

EPSS: 0.049 (92.1th percentile), scored 2026-10-24.

Low probability of exploitation in the next 30 days, but still tracked. 92nd percentile — 92.1% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.049 · newest: 0.049 · change: 0.000

Affected products

Aurelia Path — versions < 1.1.7
Bluespire Aurelia-Path

Weakness classification (CWE)

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

References

github.com/aurelia/path/security/advisories/GHSA-3c9c-2p65-qvwv (Third Party Advisory, Mitigation)
github.com/aurelia/path/issues/44 (Exploit, Third Party Advisory, Issue Tracking)
github.com/aurelia/path/commit/7c4e235433a4a2df9acc313fbe891758084fdec1 (Patch, Third Party Advisory)
github.com/aurelia/path/releases/tag/1.1.7 (Third Party Advisory, Release Notes)
www.npmjs.com/package/aurelia-path (Product, Third Party Advisory)

Frequently asked questions

What is CVE-2021-41097?: CVE-2021-41097 is a critical-severity vulnerability in Aurelia Path, classified under Improperly Controlled Modification of Object Prototype Attributes (Prototype Pollution). CVSS score: 9.1/10. Published 2021-09-27.
How severe is CVE-2021-41097?: Critical severity. CVSS v3 base score is 9.1 out of 10.