SSRF (Server-Side Request Forgery) in next (CVE-2026-64649)
Summary
SSRF in next (CVE-2026-64649). Risk of unauthorized operations or information disclosure. Exploitable via Host header. Mitigation: upgrade to 16.2.11 or later.
Original description
The description as published by the source.
Impact
When a Server Action forwards or redirects a request, an attacker can cause the server to send that outbound request to a malicious host (Server-Side Request Forgery). This requires the attacker's request to control Host-associated headers. In some configurations, it's also possible to obtain internal values that weaken middleware/proxy authorization.
Applications that use Server Actions are affected when the incoming host header is not fixed to a trusted value. This typically occurs on custom servers, or on deployments not behind a proxy that pins the host. Managed hosting pins the host upstream and is not affected; next start and standalone output do the same from version 14.2 onward.
Workarounds
If you cannot upgrade, ensure clients do not control the host header your application receives. Pin or validate Host and X-Forwarded-Host at your edge or proxy. On version 14.2.0 and later, you can additionally set the __NEXT_PRIVATE_ORIGIN environment variable to your deployment's real origin:
__NEXT_PRIVATE_ORIGIN=https://www.example.com node server.js
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-2026-64649 has been found in next.
Attackers can target a specific entry point like Host header over the network to misuse the product.
Risk of unauthorized operations or information disclosure. CVSS score: 6.5/10.
What to do: upgrade next to 16.2.11 or later.
If unsure, ask your IT team or search "next CVE-2026-64649" on the vendor's site.
CVE-2026-64649 (next) — CWE-918 / CVSS v3 6.5
Attack vector: remote (network-reachable) / unauthenticated / no user interaction
Attack surface: Host header / Host / __NEXT_PRIVATE_ORIGIN
Patched: 16.2.11 — apply immediately
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.
SSRF (CWE-918) exists in next. Attackers reach the vulnerable code path via Host header without authentication.
Check the vendor advisory for the affected versions of next. Attack surface: Host header / Host / __NEXT_PRIVATE_ORIGIN.
Severity: Medium (CVSS 6.5/10). Risk of unauthorized operations or information disclosure.
Update to 16.2.11.
Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.
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
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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 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。
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3Post-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。