Vulnerability in next (CVE-2026-64643)
Summary
Vulnerability in next (CVE-2026-64643). Risk of unauthorized operations or information disclosure. Mitigation: upgrade to 16.2.11 or later.
Original description
The description as published by the source.
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.
Source: GitHub Security Advisories (Global) NVD GitHub Advisory
Auto-generated summary
Assembled by SecPulse from the source data (CVSS, CWE, affected versions) using templates — no AI involved. Check the original description and references below for exact details.
A vulnerability tracked as CVE-2026-64643 has been found in next.
Risk of unauthorized operations or information disclosure. CVSS score: 5.3/10.
What to do: upgrade next to 16.2.11 or later.
If unsure, ask your IT team or search "next CVE-2026-64643" on the vendor's site.
CVE-2026-64643 (next) — CWE-201 / CVSS v3 5.3
Attack vector: remote (network-reachable) / unauthenticated / no user interaction
Patched: 16.2.11 — apply immediately
Workaround: Never assume any authentication claims at the use cache or use server boundary.
Plan: 1) Audit SBOM/dependencies, 2) Stage→prod upgrade, 3) Add WAF/proxy monitoring on affected endpoints, 4) Hunt IOCs in logs.
Refs: see the GHSA / vendor advisory / patched release linked on this page.
A vulnerability (CWE-201) exists in next.
Check the vendor advisory for the affected versions of next.
Severity: Medium (CVSS 5.3/10). Risk of unauthorized operations or information disclosure.
Update to 16.2.11.
Workaround: Never assume any authentication claims at the use cache or use server boundary.
Search webserver/proxy logs for unusual request patterns matching this CVE's known IOCs. Run grep -r 'next' . against your dependency files (package-lock.json, requirements.txt, go.sum) to find affected services.
Response actions
Concrete steps and command examples for SOC/SRE teams to execute in order
-
1Identify exposure identify
grep -r 'next' . | grep -v node_modulesリポジトリと本番環境の依存ファイル (package-lock.json / requirements.txt / go.sum / Gemfile.lock 等) で
nextを grep し、稼働しているサービス・バージョンを把握する。 -
2Apply temporary workaround mitigate
Never assume any authentication claims at the `use cache` or `use server` boundary.パッチが適用されるまでの応急処置として、Never assume any authentication claims at the
use cacheoruse serverboundary. を実施。回避策の副作用 (機能低下) を確認した上で。 -
3Apply patch patch
Upgrade next to 16.2.11ステージング環境で 16.2.11 に上げて回帰テスト → 本番反映。回帰テストはアプリの主要ハッピーパスを含めること。
-
4Post-deployment verification verify
Confirm patched version is live in productionパッチ適用後、ステージングで PoC または同等の悪用パターンを再現して脆弱性が閉じたことを確認。本番ではアクセスログ・WAF でアラート再発が無いか継続監視。