Critical 9.4Published Feb 4, 2026

CVE-2026-25521Locutus is vulnerable to Prototype Pollution

Updated under an hour ago (Oct 28, 2026, 3:50 AM ET)

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No exploitation reported and no EPSS estimate yet.

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Every CVE for locutusjs locutus

Exploited in the last 30 days

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 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.

CVSS: 9.4 CRITICAL (v4.0, CNA)CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H
Weakness (CWE): CWE-1321, CWE-915
Known exploited: Not in CISA's KEV catalog
EPSS (exploitation in the next 30 days): Not loaded for this CVE
Assigned by: GitHub_M
NVD analysis: Modified
Record last updated: Jul 14, 2026
First seen by InfoSec Signals: Oct 9, 2026

Affected products

Affected products

locutusjs locutus locutusjs:locutus (from the name)	from 2.0.12, < 2.0.39	CNA record
Red Hat Logging Subsystem for Red Hat OpenShift redhat:logging	5	CISA ADP
locutus locutus locutus:locutus	from 2.0.12 before 2.0.39	NVD

References

References

https://github.com/locutusjs/locutus/security/advisories/GHSA-rxrv-835q-v5mh	x-refsource-confirm, exploit, vendor-advisory
https://github.com/locutusjs/locutus/commit/042af9ca7fde2ff599120783e720a17f335bb01c	x-refsource-misc, patch
https://access.redhat.com/security/cve/CVE-2026-25521
https://bugzilla.redhat.com/show_bug.cgi?id=2436950
https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-25521.json

The CVE record on cve.org NVD's entry

The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.