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Medium

Next.js: Unauthenticated disclosure of internal Server Function endpoints

  • Disclosed: 22.07.2026
  • Updated: 11.10.2026 10:22

Impact

In 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 + Server Actions.

By itself, this disclosure is typically a recon/enumeration primitive; however, it can increase risk when combined with other weaknesses.

Workarounds

Never assume any authentication claims at the use cache or use server boundary. Always authenticate within the boundary.

Affected software

Click a technology to see all vulnerabilities affecting it.

PlatformPackageVulnerable versionsFixed in
npm package next >= 13.0.0, < 15.5.21, >= 16.0.0, < 16.2.11 15.5.21, 16.2.11

References

CVSS score -
CVSS vector
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
Weakness (CWE)
CWE-201
Platform
npm
Package
next
Disclosed
22.07.2026
Updated
11.10.2026 10:22

Sources and licenses

OSV / GitHub Advisory Database - GHSA-955p-x3mx-jcvp - CC BY 4.0

Vulnerability history: next

All published vulnerabilities of this package (npm package), newest first. Shows whether this is a one-off slip or a package that needs watching.

All (73) in the archive
Total entries
73
First → latest
12.2017 10.2026
Without a fix
0
Exploited in attacks
0

Severity breakdown

  • Critical 5
  • High 27
  • Medium 32
  • Low 9

Disclosures per year

Severity:
  1. Next.js has Server-Side Request Forgery in Image Optimization
    High · 6.5 CVE-2026-94483 >= 16.0.0, < 16.3.8 16.3.8
  2. Next.js: Remote Code Execution in next/og ImageResponse
    Critical ghsa-vcvr-r3jv-pc5j >= 16.2.0, < 16.3.6 16.3.6
  3. Next.js: Unauthenticated Remote Code Execution in Image Optimization API when AVIF files are used
    Critical ghsa-2xp9-vwfh-vxw4 >= 10.0.0, < 15.5.24, >= 16.0.0, < 16.3.3 15.5.24, 16.3.3
  4. Next.js: Unauthenticated Remote Code Execution on windows-hosted servers
    Critical · 9.0 CVE-2026-75604 >= 13.4.0, < 15.5.24, >= 16.0.0, < 16.3.3 15.5.24, 16.3.3
  5. Next.js: Server-Side Request Forgery in Server Actions on custom servers
    High CVE-2026-64649 >= 14.1.1, < 15.5.21, >= 16.0.0, < 16.2.11 15.5.21, 16.2.11
  6. Next.js: Server-Side Request Forgery in rewrites via attacker-controlled destination hostname
    High CVE-2026-64645 >= 12.0.0, < 15.5.21, >= 16.0.0, < 16.2.11 15.5.21, 16.2.11
  7. Next.js: Unauthenticated disclosure of internal Server Function endpoints this entry
    Medium CVE-2026-64643 >= 13.0.0, < 15.5.21, >= 16.0.0, < 16.2.11 15.5.21, 16.2.11
  8. Next.js: Middleware / Proxy bypass in App Router applications using Turbopack and single locale
    High CVE-2026-64642 >= 16.0.0, < 16.2.11 16.2.11
  9. Next.js: Denial of Service in App Router using Server Actions
    High CVE-2026-64641 >= 13.0.0, < 15.5.21, >= 16.0.0, < 16.2.11 15.5.21, 16.2.11
  10. Next.js has a Middleware / Proxy bypass in App Router applications via segment-prefetch routes - Incomplete Fix Follow-Up
    High · 7.5 CVE-2026-45109 >= 15.2.0, < 15.5.18, >= 16.0.0, < 16.2.6 15.5.18, 16.2.6
  11. Next.js vulnerable to Denial of Service via connection exhaustion in applications using Cache Components
    High · 7.5 CVE-2026-44579 >= 15.0.0, < 15.5.16, >= 16.0.0, < 16.2.5 15.5.16, 16.2.5
  12. Next.js vulnerable to server-side request forgery in applications using WebSocket upgrades
    High · 8.6 CVE-2026-44578 >= 13.4.13, < 15.5.16, >= 16.0.0, < 16.2.5 15.5.16, 16.2.5
  13. Next.js has a Middleware / Proxy bypass in App Router applications via segment-prefetch routes
    High · 7.5 CVE-2026-44575 >= 15.2.0, < 15.5.16, >= 16.0.0, < 16.2.5 15.5.16, 16.2.5
  14. Next.js has a Middleware / Proxy bypass through dynamic route parameter injection
    High · 8.1 CVE-2026-44574 >= 15.4.0, < 15.5.16, >= 16.0.0, < 16.2.5 15.5.16, 16.2.5
  15. Next.js has a Middleware / Proxy bypass in Pages Router applications using i18n
    High · 7.5 CVE-2026-44573 >= 12.2.0, < 15.5.16, >= 16.0.0, < 16.2.5 15.5.16, 16.2.5
  16. Next.js Vulnerable to Denial of Service with Server Components
    High · 7.5 ghsa-8h8q-6873-q5fj >= 13.0.0, < 15.5.16, >= 16.0.0, < 16.2.5 15.5.16, 16.2.5
  17. Next.js has a Denial of Service with Server Components
    High · 7.5 ghsa-q4gf-8mx6-v5v3 >= 13.0.0, < 15.5.15, >= 16.0.0-beta.0, < 16.2.3 15.5.15, 16.2.3
  18. Next.js HTTP request deserialization can lead to DoS when using insecure React Server Components
    High · 7.5 ghsa-h25m-26qc-wcjf >= 13.0.0, < 15.0.8, >= 15.1.1-canary.0, < 15.1.12, >= 15.2.0-canary.0, < 15.2.9, >= 15.3.0-canary.0, < 15.3.9, >= 15.4.0-canary.0, < 15.4.11, >= 15.5.1-canary.0, < 15.5.10, >= 15.6.0-canary.0, < 15.6.0-canary.61, >= 16.0.0-beta.0, < 16.0.11, >= 16.1.0-canary.0, < 16.1.5 15.0.8, 15.1.12, 15.2.9, 15.3.9, 15.4.11, 15.5.10, 15.6.0-canary.61, 16.0.11, 16.1.5
  19. Next has a Denial of Service with Server Components - Incomplete Fix Follow-Up
    High · 7.5 ghsa-5j59-xgg2-r9c4 >= 13.3.1-canary.0, < 14.2.35, >= 15.0.6, < 15.0.7, >= 15.1.10, < 15.1.11, >= 15.2.7, < 15.2.8, >= 15.3.7, < 15.3.8, >= 15.4.9, < 15.4.10, >= 15.5.8, < 15.5.9, >= 15.6.0-canary.59, < 15.6.0-canary.60, >= 16.0.9, < 16.0.10, >= 16.1.0-canary.17, < 16.1.0-canary.19 14.2.35, 15.0.7, 15.1.11, 15.2.8, 15.3.8, 15.4.10, 15.5.9, 15.6.0-canary.60, 16.0.10, 16.1.0-canary.19
  20. Next Vulnerable to Denial of Service with Server Components
    High · 7.5 ghsa-mwv6-3258-q52c >= 13.3.0, < 14.2.34, >= 15.0.0-canary.0, < 15.0.6, >= 15.1.1-canary.0, < 15.1.10, >= 15.2.0-canary.0, < 15.2.7, >= 15.3.0-canary.0, < 15.3.7, >= 15.4.0-canary.0, < 15.4.9, >= 15.5.1-canary.0, < 15.5.8, >= 15.6.0-canary.0, < 15.6.0-canary.59, >= 16.0.0-beta.0, < 16.0.9, >= 16.1.0-canary.0, < 16.1.0-canary.17 14.2.34, 15.0.6, 15.1.10, 15.2.7, 15.3.7, 15.4.9, 15.5.8, 15.6.0-canary.59, 16.0.9, 16.1.0-canary.17
Show more (13) Showing 20 of 33

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