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TI-2026-20630 Aliases CVE-2026-25521GHSA-rxrv-835q-v5mh

Locutus is vulnerable to Prototype Pollution

Priority MEDIUM 42CWE-1321Published · Updated

Key facts

Attack vector
Local
Privileges required
None
User interaction
None
Attack complexity
Low
Attack requirements
None
Impact type
Tampering
Confidentiality · integrity · availability
High · High · High
Fix status
Fixed

Attack profile from CVSS 4.0 · CNA. Fix status from CNA and GitHub. Impact type from CWE-915.

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 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.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00314 24th percentileScored 2026-11-07
Public exploit Yes 1 exploit referenceTagged by NVD
Fix Fixed locutus (locutusjs): 2.0.39locutus (npm): 2.0.39

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
No
Technical impact
Total

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
locutusjslocutus2.0.12 to before 2.0.392.0.39Patch availableCNA
—locutus (npm)2.0.12 to before 2.0.392.0.39Patch availableGHSA-rxrv-835q-v5mh
  • locutus Vendorlocutusjs Affected 2.0.12 to before 2.0.39 Fixed in 2.0.39 Patch available CNA
  • locutus (npm) Vendor— Affected 2.0.12 to before 2.0.39 Fixed in 2.0.39 Patch available GHSA-rxrv-835q-v5mh

CPE configurations NVD · 1

CPEVersionsRoleVendor
cpe:2.3:a:locutus:locutus:*:*:*:*:*:node.js:*:*2.0.12 to before 2.0.39Vulnerablelocutusjs
  • cpe:2.3:a:locutus:locutus:*:*:*:*:*:node.js:*:* Versions 2.0.12 to before 2.0.39 Vulnerable ·locutusjs

Remediation

  • Fix · CNA locutus (locutusjs) Fixed in 2.0.39
  • Fix · GHSA-rxrv-835q-v5mh locutus (npm) Fixed in 2.0.39 Advisory →

Vendor assessments

Red Hat

Red Hat rating: Critical. Red Hat's page for this CVE →

Not affected: 1 product
  • Logging Subsystem for Red Hat OpenShift

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-25521
  2. 2026-10-03 Alias added: GHSA-rxrv-835q-v5mh
  3. 2026-10-05 Weakness changed · GHSA-rxrv-835q-v5mh
  4. 2026-10-05 3 new references · GHSA-rxrv-835q-v5mh

References

Exploit 1

Patch 1

Advisory 1

Other 4

  • TI-2026-24833 Locutus: RCE via unsanitized input in create_function() CVSS 3.1CRITICAL 9.8
  • TI-2026-26333 Locutus has Prototype Pollution via __proto__ Key Injection in unserialize() CVSS 4.0MEDIUM 6.9
  • TI-2026-23234 Locutus: Remote Code Execution (RCE) in locutus call_user_func_array due to Code Injection CVSS 3.1HIGH 8.1
  • TI-2026-26334 Locutus Prototype Pollution due to incomplete fix for CVE-2026-25521 CVSS 4.0MEDIUM 6.3
  • TI-2020-06239 Prototype pollution in locutus CVSS 3.1CRITICAL 9.8
  • TI-2021-06085 Regular expression denial of service (ReDoS) in locutus CVSS 3.1HIGH 7.5

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences