ZDF
Sign inSign up

Vulnerabilities

Vulnerability · CVE-2026-25521

Locutus brings stdlibs of other programming languages to JavaScript for educational purposes.

Published Feb 4, 2026 · catalog updated Jul 15, 2026 · Locutus brings stdlibs of

Last checked Nov 5, 2026. A connected source was read within the last 7 days.

Check if you run it

No confirmed exploitation is on record for CVE-2026-25521. EPSS is 0.31%. Act only if a listed version of Locutus brings stdlibs of is installed.

Gaps on this record

  • The stored product name is a package slug. The name on this page is taken from the title (Locutus brings stdlibs of).
  • No vendor fix or required action is stored. Compare the linked advisory before you change production.

Same product and reporting

Severity
Critical9.4
Known exploitation
Not in CISA/VulnCheck KEV
EPSS
0.31%
Remediation
Version ranges on file
Affected products
vendor locutusjs locutus 2.0.12, < 2.0.39

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.

Are you affected?

Enter the version you run. The result uses only the ranges stored on this record.

The check returns affected, not affected, or incomplete. It does not guess a version that is missing from the record.

  • vendor locutusjs locutus 2.0.12, < 2.0.392.0.12, < 2.0.39

How to fix CVE-2026-25521

What to do

Three questions, each answered from this record only. Confirm the vendor advisory before you patch.

Should you patch?

No confirmed exploitation is on record for CVE-2026-25521. EPSS is 0.31%. Act only if a listed version of Locutus brings stdlibs of is installed.

Which versions are affected?

Compare what you have installed with locutusjs locutus 2.0.12, < 2.0.39 2.0.12, < 2.0.39. Compare the installed version with the linked vendor advisory before you change production.

What should an analyst verify?

No weakness class is stored. EPSS 0.31%. There is no CISA KEV listing. No Exploit-DB or Metasploit reference is linked. Use the source links for the original advisory.

Code

The project this record applies to. Exploit listings stay in References.

Timeline

Detection, updates, and resolution for this record.

  1. Feb 4, 2026 · EUVD

    Detected

    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

  2. Jul 15, 2026 · EUVD

    Updated

    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

Sources

  • CVE.orgVulnerability recordCVE-2026-25521

    Official CVE identifier

    cve.org
  • FIRST EPSSExploitation probabilityCVE-2026-25521

    30-day exploitation probability 0.31%

    first.org
  • EUVDVulnerability recordEUVD-2026-5340

    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

    euvd.enisa.europa.eu

References

Freshness

Last verified in this catalog Nov 5, 2026. Significant claims (KEV, EPSS, CVSS, affected ranges) come from the source rows above — open the original publisher for the authoritative advisory.

  • FIRST EPSSNov 5, 2026
  • CVE.orgNov 4, 2026
  • EUVDNov 2, 2026