by Kastro
Paper/Archive/CVE-2026-25521

CVE-2026-25521

locutusjs locutus — Locutus is vulnerable to Prototype Pollution

EPSS 0.3%CVSS 9.4
critical.is priorityof 100
33
CVSS 9.4 (CNA)9.4 / 10 × 3028.2Not in CISA KEV+300.0EPSS percentile 24.4.244 × 204.9No public exploit+100.0SSVC exploitation: none+100.0
Description · from the CVE record

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.

Affected

ProductAffectedFixed inSource
locutus>= 2.0.12, < 2.0.39–CNA
Logging Subsystem for Red Hat OpenShiftsee advisory–redhat-SADP
Logging Subsystem for Red Hat OpenShiftsee advisory–redhat-SADP
Logging Subsystem for Red Hat OpenShiftsee advisory–redhat-SADP
Logging Subsystem for Red Hat OpenShiftsee advisory–redhat-SADP
Logging Subsystem for Red Hat OpenShiftsee advisory–redhat-SADP
Logging Subsystem for Red Hat OpenShiftsee advisory–redhat-SADP

Scores by source

GitHub_M (CNA)9.4CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H
redhat-SADP (CNA)9.3CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H
CISA ADPSSVCExploitation: none · Automatable: no · Technical impact: total

References

refgithub.com/locutusjs/locutus/security/advisories/GHSA-rxrv-835q-v5mhrefgithub.com/locutusjs/locutus/commit/042af9ca7fde2ff599120783e720a17f335bb01crefaccess.redhat.com/security/cve/CVE-2026-25521refbugzilla.redhat.com/show_bug.cgi?id=2436950refsecurity.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-25521.json