CVE-2026-103004: Next.js versions from 16.3.0 to 16.3.7 warm `use cache` handlers using `next/root-params` and can leak their return value to pages with different root params.

Next.js versions from 16.3.0 to 16.3.7 warm `use cache` handlers using `next/root-params` and can leak their return value to pages with different root params.

Next.js versions from 16.3.0 to 16.3.7 warm `use cache` handlers using `next/root-params` and can leak their return value to pages with different root params. With Cache Components enabled (cacheComponents: true), a 'use cache' function that calls another 'use cache' function that reads a root param can be keyed incorrectly when the inner call is served from an existing entry: the enclosing function's cache key then omits that root param. The enclosing entry is written once and reused for all root param values, so a response for one root param value can serve content produced for a different value — whether the page is prerendered at build time or at runtime, or rendered dynamically. Shared cache headers let downstream caches redistribute the content further. What values are leaked cannot be attacker controlled. Which value's content is served depends only on which invocation wrote the entry first. This has been patched in 16.3.8.

Description from the National Vulnerability Database, published by GitHub

What it means for a small business

If your business uses next.js, install the vendor's update. If you're not sure whether you use it, ask whoever manages your computers.

How likely is an attack? The Exploit Prediction Scoring System, run by FIRST (the global association of security response teams), puts the odds of this one being exploited in the next 30 days at 0.25%, higher than 16% of CVEs. That’s low, but low isn’t zero, and the odds jump the day someone publishes an exploit. Scored October 28, 2026, updated daily.

Check your own setup

Website check: reads what your site runs from the outside (WordPress version, plugins it can see, old server software) and matches it against this database.
Server check: what your web server says about itself, and whether that version has known flaws.

Sources

Part of the Huttenlocher Technologies vulnerability database, refreshed twice a day from CISA and the NVD. The title, category and plain-language guidance are ours; check the linked record before acting on a detail. This is general guidance, not a review of your systems.

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