CVE-2026-64643: medium-severity vulnerability in vercel next.js
Next.js: Unauthenticated Disclosure of Internal Server Function endpoints
Published
E-mail alert when it lands in KEV, gets a public PoC or its score goes up.
13Vexday Risk Score
No sign of exploitation. No public exploitation artifact known so far.
ssvc Trackcvss 6.3epss 0.5%
Next.js is a React framework for building full-stack web applications. In versions 12.0.0 through 15.5.20 and 16.0.0 through 16.2.10, Next.js applications using App Router, Server Actions (use server) or use cache endpoints can be disclosed bypassing any authentication on the pages where these endpoints are usually used. Server Action IDs can be disclosed to unauthenticated users via publicly served client artifacts (for example, static chunks containing action references). Affected users are applications using App Router and Server Actions. By itself, this disclosure is typically a recon/enumeration primitive; however, it can increase risk when combined with other weaknesses. This issue has been fixed in versions 15.5.21 and 16.2.11.
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N
Affected products
vercel · next.jsRelated CVEs — vercel next.js
In the same product, most dangerous first.
CVE-2025-29927CRITICALAuthorization Bypass in Next.js MiddlewareEPSS 99.2%CVE-2024-46982HIGHCache Poisoning in next.jsEPSS 59.2%CVE-2021-43803HIGHUnexpected server crash in Next.jsEPSS 47.3%CVE-2026-44578HIGHNext.js: Server-side request forgery in applications using WebSocket upgradesEPSS 35.5%CVE-2024-34351HIGHNext.js Server-Side Request Forgery in Server ActionsEPSS 5.5%CVE-2024-51479HIGHAuthorization bypass in Next.jsEPSS 4.0%
References
https://github.com/vercel/next.js/commit/1b0c3ae912a3ad925c60065cc8d55b070fa8bcd3https://github.com/vercel/next.js/commit/ff12a6124e1504f17b62de948b8a553fdecaef7bhttps://github.com/vercel/next.js/releases/tag/v15.5.21https://github.com/vercel/next.js/releases/tag/v16.2.11https://github.com/vercel/next.js/security/advisories/GHSA-955p-x3mx-jcvp