GHSA-6gpp-xcg3-4w24: Next.js: Middleware / Proxy bypass in App Router applications using Turbopack and single locale
Impact
Crafted requests targeting Next.js applications using App Router built with Turbopack and a single entry in config.i18n.locales can bypass middleware/proxy based authentication.
Workarounds
If you cannot upgrade immediately, enforce authorization in the page's server-side data path instead of relying solely on middleware.
Details
Original advisory: https://github.com/advisories/GHSA-6gpp-xcg3-4w24
Exploitation outlook
EPSS (FIRST.org) estimates each CVE’s probability of exploitation in the next 30 days — here is the CSIRTS.com read on those numbers.
- Low exploitation riskCVE-2026-646420.95% 30-day exploitation probability — currently an unlikely target, but scores change as exploit code circulates. Riskier than 58% of all scored CVEs.
Referenced CVEs
| CVE | CSIRTS overview | External |
|---|---|---|
| CVE-2026-64642 | coverage & exploitation status | NVD · CVE.org |
Same CVEs, other sources
How other CERTs, PSIRTs and databases cover the vulnerabilities in this advisory.
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