Predictive Vulnerability Intelligence.

Product

  • Product
  • Pricing
  • Documentation

Company

  • About
  • Partnerships
  • Blog
  • Support

Legal

  • Terms
  • Privacy
  • Data Licensing

© 2026 FAUCET Technologies LLC. All rights reserved.

CVE-2021-26505

25
FAUCET Score

CVE-2021-26505 is a critical prototype pollution vulnerability in MrSwitch hello.js version 1.18.6, allowing remote attackers to execute arbitrary code through the hello.utils.extend function. With a CVSS score of 9.8, it presents a high-severity risk due to its network-based attack vector, low attack complexity, and complete compromise of confidentiality, integrity, and availability. Despite its critical nature, there is currently no evidence of active exploitation, publicly available exploit code (Metasploit, Nuclei, ExploitDB), or significant community discussion or media coverage.

Impacted Technologies

VendorProductVersion(s)CPE
1.18.6CPE matchmatch criteria
cpe:2.3:a:hello.js_project:hello.js:1.18.6:*:*:*:*:node.js:*:*

CVSS Data

CVSS version used by this source: 3.1

9.8CRITICAL

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality Impact
HIGH
Integrity Impact
HIGH
Availability Impact
HIGH
Exploitability Score
3.9
Impact Score
5.9
CvssVersion
3.1

Exploit Intelligence

EPSS Score
0.95%
Probability of exploitation in next 30 days
EPSS Percentile
57.7%
Percentile rank of EPSS score among Peer Group
As of 2026-07-27
Model: v2026.06.15
This CVE's current EPSS score of 0.0095 is in the 43rd percentile among its peer group of 36,897 CVEs.

Social Chatter

The average CVE in this peer group has 0.0 Twitter, 0.1 Reddit, 0.3 Bluesky, 0.3 Mastodon, and 2.4 GitHub mentions.

Media Mentions

No media coverage found for this CVE.

The average CVE in this peer group has 0.3 InfoSec Media, 0.0 Vendor Blog, and 0.0 Security Researcher mentions.

Remediation

Patch Available

Vendor Patches (1)

npmpatch availablevia ghsa
Product: hellojsFixed in: 1.18.8

Vendor Advisories (1)

npmGHSA-g3vf-47fv-8f3ccritical

MrSwitch hello.js vulnerable to prototype pollution

Aug 11, 2023

References

github.com / MrSwitch/hello.js/issues/634
Issue Tracking