CVE-2026-25521
critical · 9.4Locutus 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.
9.4
CVSS
0.3%
EPSS (exploit prob.)
21st
EPSS percentile
2026-02-04
Published
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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
Weaknesses
CWE-1321CWE-915
Affected products
| Vendor | Product | Affected versions |
|---|---|---|
| locutus | locutus | >= 2.0.12, < 2.0.39 |
Check a specific version with /api/v1/cve/match.
References
- https://github.com/locutusjs/locutus/commit/042af9ca7fde2ff599120783e720a17f335bb01c
- https://github.com/locutusjs/locutus/security/advisories/GHSA-rxrv-835q-v5mh
- 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
Query this programmatically:
curl https://evil-db.io/api/v1/cve/CVE-2026-25521