Vulnerability in next (CVE-2026-44576)
Summary
Vulnerability in next (CVE-2026-44576). Risk of unauthorized operations or information disclosure. Exploitable via RSC. Mitigation: upgrade to 16.2.5 or later.
Original description
The description as published by the source.
Impact
Applications using React Server Components can be vulnerable to cache poisoning when shared caches do not correctly partition response variants. Under affected conditions, an attacker can cause an RSC response to be served from the original URL and poison shared cache entries so later visitors receive component payloads instead of the expected HTML.
Fix
We now validate and interpret RSC request headers consistently across request classification and rendering, and we enforce the intended cache-busting behavior so RSC payloads are not unexpectedly served from the original URL.
Workarounds
If you cannot upgrade immediately, ensure your CDN or reverse proxy keys on the relevant RSC request headers and honors Vary, or disable shared caching for affected App Router and RSC responses.
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-2026-44576 has been found in next.
Attackers can target a specific entry point like RSC over the network to misuse the product.
Risk of unauthorized operations or information disclosure. CVSS score: 5.4/10.
What to do: upgrade next to 16.2.5 or later.
If unsure, ask your IT team or search "next CVE-2026-44576" on the vendor's site.
CVE-2026-44576 (next) — CWE-436 / CVSS v3 5.4
Attack vector: remote (network-reachable) / unauthenticated / no user interaction
Attack surface: RSC / Vary
Patched: 16.2.5 — apply immediately
Workaround: If you cannot upgrade immediately, ensure your CDN or reverse proxy keys on the relevant RSC request headers and honors Vary, or disable shared caching for affected App Router and RSC responses.
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-436) exists in next. Attackers reach the vulnerable code path via RSC without authentication.
Check the vendor advisory for the affected versions of next. Attack surface: RSC / Vary.
Severity: Medium (CVSS 5.4/10). Risk of unauthorized operations or information disclosure.
Update to 16.2.5.
Workaround: If you cannot upgrade immediately, ensure your CDN or reverse proxy keys on the relevant RSC request headers and honors Vary, or disable shared caching for affected App Router and RSC responses.
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
If you cannot upgrade immediately, ensure your CDN or reverse proxy keys on the relevant RSC request headers and honors `Vary`, or disable shared caching for affected App Router and RSC responses.パッチが適用されるまでの応急処置として、If you cannot upgrade immediately, ensure your CDN or reverse proxy keys on the relevant RSC request headers and honors
Vary, or disable shared caching for affected App Router and RSC responses. 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 16.2.5ステージング環境で 16.2.5 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。
Affected packages
References
- advisory nvd.nist.gov
- package github.com
- web github.com
- web github.com
- web github.com
- web github.com