{"id":"CVE-2026-25521","title":"Locutus brings stdlibs of other programming languages to JavaScript for educational purposes","summary":"Locutus brings stdlibs of other programming languages to JavaScript for educational purposes. In versions from 2.0.12 to before 2.0.39, a prototype pollution vulnerability exists in locutus. Despite a previous fix that attempted to mitig…","severity":"high","cvss":8.8,"cvssVector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H","cwe":["CWE-1321","CWE-915"],"vendor":"locutus","product":"locutus","affected":["locutus >= 2.0.12, < 2.0.39"],"patched":["locutus 2.0.39"],"published":"2026-02-04","updated":"2026-06-27","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-25521","references":[{"url":"https://github.com/locutusjs/locutus/commit/042af9ca7fde2ff599120783e720a17f335bb01c","label":"security-advisories@github.com"},{"url":"https://github.com/locutusjs/locutus/security/advisories/GHSA-rxrv-835q-v5mh","label":"security-advisories@github.com"},{"url":"https://access.redhat.com/security/cve/CVE-2026-25521","label":"0b0ca135-0b70-47e7-9f44-1890c2a1c46c"},{"url":"https://bugzilla.redhat.com/show_bug.cgi?id=2436950","label":"0b0ca135-0b70-47e7-9f44-1890c2a1c46c"},{"url":"https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-25521.json","label":"0b0ca135-0b70-47e7-9f44-1890c2a1c46c"}],"tags":["nvd"],"epss":0.00444,"epssPercentile":0.35905,"ingestedAt":"2026-06-29T13:24:34.638Z","slug":"CVE-2026-25521","body":"## Overview\n\nLocutus brings stdlibs of other programming languages to JavaScript for educational purposes. In versions from 2.0.12 to before 2.0.39, a prototype pollution vulnerability exists in locutus. Despite a previous fix that attempted to mitigate prototype pollution by checking whether user input contained a forbidden key, it is still possible to pollute Object.prototype via a crafted input using String.prototype. This issue has been patched in version 2.0.39.\n\n## Affected\n\n- `locutus >= 2.0.12, < 2.0.39`\n\n## Remediation\n\nUpgrade past the affected range:\n\n- `locutus 2.0.39`","depth":"twilight","depthScore":48,"depthScoreParts":{"impact":48.4,"likelihood":0.1,"exploitation":0,"ransomware":0},"changes":[]}