{"cve":"CVE-2021-26505","nvd":{"published":"2023-08-11T14:15:12.257","modified":"2026-06-17T03:43:26.813","status":"Modified","description":"Prototype pollution vulnerability in MrSwitch hello.js version 1.18.6, allows remote attackers to execute arbitrary code via hello.utils.extend function.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","score":9.8},"cwes":["CWE-1321"],"references":["https://github.com/MrSwitch/hello.js/issues/634","https://github.com/MrSwitch/hello.js/issues/634"],"products":["hello.js_project:hello.js"],"source":"nvd","synced_at":"2026-10-19T21:39:14.809778102+00:00"},"epss":{"cve":"CVE-2021-26505","score":0.01144,"percentile":0.6672,"date":"2026-10-31"},"kev":null,"osv":[{"id":"GHSA-g3vf-47fv-8f3c","url":"https://osv.dev/vulnerability/GHSA-g3vf-47fv-8f3c","summary":"MrSwitch hello.js vulnerable to prototype pollution","modified":"2023-11-08T04:05:21.032993Z","packages":[{"ecosystem":"npm","name":"hellojs","purl":"pkg:npm/hellojs","ranges":["<1.18.8"],"fixed":["1.18.8"]}]}],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}