Cross-site Scripting (XSS)

published 2020-10-06 6 y ago modified 2026-07-08 4 mo ago also GHSA-7jh9-6cpf-h4m7 , EUVD-2021-0496

cvss: 9.9; version 3.1, CNA
cisa kev: Not listed; not in CISA's catalog
epss: 1.5%; EPSS 1.5% chance of exploitation in 30 days, percentile 74%
public exploits: 0; none known

This affects the package hellojs before 1.18.6. The code get the param oauth_redirect from url and pass it to location.assign without any check and sanitisation. So we can simply pass some XSS payloads into the url param oauth_redirect, such as javascript:alert(1).

Patch / fix

fixed in 2 links 1

npm hellojs 1.18.6
n/a hellojs 1.18.6

github.com/MrSwitch/hello.js@d6f5137 commit

Exploit prediction

1.48% chance of exploitation in the next 30 days, higher than 74% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by	version	score	vector
CNA	3.1	9.9	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:H
NVD	2.0	7.5	AV:N/AC:L/Au:N/C:P/I:P/A:P
GitHub	3.1	9.9	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:H

Affected packages

ecosystem	package	affected	fixed in
npm	hellojs	<1.18.6	1.18.6

Affected products

n/a hellojs

Classification

Weakness

CWE-79 Improper Neutralization of Input During Web Page Generation

References

github.com /MrSwitch/hello.js/commit/d6f5137f30de6e0ef7048191ee6ae575fdc2f669
web, patch, third-party-advisory
snyk.io /vuln/SNYK-JS-HELLOJS-1014546
web, third-party-advisory
github.com /MrSwitch/hello.js/blob/3b79ec93781b3d7b9c0b56f598e060301d1f3e73/dist/hello.all.js%23L1545
web, broken-link
nvd.nist.gov /vuln/detail/CVE-2020-7741
advisory

Sources

CVE List CVE-2020-7741
GitHub Advisory GHSA-7jh9-6cpf-h4m7
NVD CVE-2020-7741

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