CVE-2026-48714
Remote prototype pollution via missingKeyHandler in i18next-http-middleware (pre-3.9.7) with untrusted input.
Is CVE-2026-48714 being exploited?
Not confirmed. CVE-2026-48714 does not appear in CISA's Known Exploited Vulnerabilities catalog, which records only exploitation that has been observed and reported publicly. That is evidence of absence of a report, not evidence the flaw is unattacked. EPSS currently estimates a 0.51% probability of exploitation in the next 30 days.
How severe is CVE-2026-48714?
CVE-2026-48714 is rated Critical with a CVSS score of 9.1. Severity describes how bad exploitation would be, not how likely it is: pair it with exploitation evidence before deciding what to patch first.
Is there a patch for CVE-2026-48714?
Yes. A fix has been recorded for CVE-2026-48714. The vendor advisory is the authority on the exact fixed version — apply it from there rather than from a summary.
What does CVE-2026-48714 affect?
CVE-2026-48714 affects i18next-http-middleware (pre-3.9.7), i18next-fs-backend <= 2.6.5, Node.js web apps (Express/Fastify). Confirm the exact affected versions against the vendor advisory before deciding you are exposed.
What should I do about CVE-2026-48714?
Upgrade to 3.9.7+; restrict exposure; filter top-level keys; disable missing-key persistence.
Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.
Allows remote prototype pollution of Object.prototype via missingKeyHandler with untrusted input; can crash, corrupt translations, and bypass checks.
Patch when possible
- affected< 3.9.7
As published in the CVE Program record. A version outside these ranges is not a statement that it is unaffected — vendors sometimes understate a range, and distribution-backported builds carry upstream numbers that do not reflect what was patched into them.