CVE-2026-103004: next.js — Fix

Description

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.

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CVSS v3.1 Score

5.3

MEDIUM

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N

EPSS — Exploit Prediction

0.0025

Probability of exploitation

0.15%

Percentile rank

EPSS estimates the probability that this vulnerability will be exploited in the wild within the next 30 days. A higher score means more likely to be exploited.

Weakness Type (CWE)

CWE-524 CWE-524

Affected Products

Vendor	Product	Versions
vercel	next.js	16.3.0 — 16.3.8

References

Advisories & Patches

https://github.com/vercel/next.js/security/advisories/GHSA-h694-7cp9-m8p3

Other References

https://github.com/vercel/next.js/releases/tag/v16.3.8

Frequently Asked Questions

What is 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. 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. It has a CVSS v3.1 base score of 5.3 (MEDIUM).

How severe is CVE-2026-103004? +

CVE-2026-103004 has a CVSS v3.1 score of 5.3 out of 10, rated MEDIUM. This is a medium-severity vulnerability that should be remediated as part of regular maintenance. The EPSS score is 0.0025, placing it in the 0th percentile for exploitation probability.

What products are affected by CVE-2026-103004? +

CVE-2026-103004 affects products from vercel, specifically: next.js. Check the affected products table above for specific version ranges.

How do I check if I'm vulnerable to CVE-2026-103004? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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