PatchTheCVECVE-2026-48714: i18next-http-middleware is a middleware to be used with Node.js web frameworks like express or Fastify and als
CVE-2026-48714 is a critical-severity flaw (CVSS 9.1) affecting i18next-http-middleware. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.
i18next-http-middleware is a middleware to be used with Node.js web frameworks like express or Fastify and also for Deno. In versions prior to 3.9.7, the missingKeyHandler blocked the literal request-body keys __proto__, constructor, and prototype (added in 3.9.3, see GHSA-5fgg-jcpf-8jjw), but did not reject dotted variants such as "__proto__.polluted". Downstream backends that split the missing-key string on a configured keySeparator (notably i1
Why this priority
- Critical severity
- Remotely exploitable, no login, no user action
A fixed release or distro patch exists.
Risk facts
| CVSS score | 9.1 (Critical) |
| Attack vector | Network (remote) |
| Attack complexity | Low |
| Privileges needed | None |
| User interaction | None |
| EPSS exploit chance | 0.5% (top 57%) |
| CISA exploited list | No |
| Weakness | CWE-1321 |
| Published | 2026-06-15 |
| Last modified | 2026-10-25 |
Last updated 2026-10-25 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score
Am I affected?
Timeline
- Published CVE record published
- Updated Record last modified
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.
Quick answers
How do I fix CVE-2026-48714?
i18next-http-middleware: upgrade to 3.9.7. Exact commands for each OS are on this page.
Is CVE-2026-48714 being exploited?
CVE-2026-48714 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.
What does CVE-2026-48714 affect?
CVE-2026-48714 affects i18next-http-middleware. Severity is critical (CVSS 9.1). i18next-http-middleware is a middleware to be used with Node.js web frameworks like express or Fastify and also for Deno. In versions prior to 3.9.7, the missingKeyHandler blocked the literal request-body keys __proto__, constructor, and pr
How urgent is CVE-2026-48714?
Priority 48/100. Critical severity; Remotely exploitable, no login, no user action