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CVE-2026-34077
high
CVSS 7.5
Vulnerability in react-router (CVE-2026-34077)
Summary
vulnerability in react-router (CVE-2026-34077). Risk of unauthorized operations or information disclosure. Exploitable via ``createBrowserRouter``. Mitigation: upgrade to `7.14.0` or later.
AI summary snake-internal / snake-material-v2
A vulnerability tracked as **CVE-2026-34077** has been found in react-router.
Attackers can target a specific entry point like ``createBrowserRouter`` over the network to misuse the product.
Risk of unauthorized operations or information disclosure. CVSS score: 7.5/10.
What to do: upgrade react-router to **7.14.0** or later.
If unsure, ask your IT team or search "react-router CVE-2026-34077" on the vendor's site.
CVE-2026-34077 (react-router) — CWE-770 / CVSS v3 7.5
Attack vector: remote (network-reachable) / unauthenticated / no user interaction
Attack surface: `createBrowserRouter`
Patched: `7.14.0` — 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.
❓ What is the problem
**A vulnerability** (CWE-770) exists in react-router. Attackers reach the vulnerable code path via ``createBrowserRouter`` without authentication.
📍 Affected scope
react-router — . Attack surface: `createBrowserRouter`.
🔥 Severity
Severity: High (CVSS 7.5/10). Risk of unauthorized operations or information disclosure
🔧 How to fix
Update to **7.14.0**.
🛡️ Workaround
Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.
🔍 Detection
Search webserver/proxy logs for unusual request patterns matching this CVE's known IOCs. Run `grep -r 'react-router' .` against your dependency files (package-lock.json, requirements.txt, go.sum) to find affected services.
Response Actions (7 steps)
Concrete steps and command examples for SOC/SRE teams to execute in order
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1Identify exposure identify
grep -r 'react-router' . | 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 `react-router` を grep し、稼働しているサービス・バージョンを把握する。
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6Apply patch patch
Upgrade react-router to 7.14.0ステージング環境で 7.14.0 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と、Step 3 で見つけた異常検知の続報チェックを含めること。
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7Post-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 Step 3 と同じログクエリでアラート再発が無いか継続監視。
Affected packages
npm
react-router
[{"type":"SEMVER","events":[{"introduced":"7.0.0"},{"fixed":"7.14.0"}]}]
npm
turbo-stream
[{"type":"SEMVER","events":[{"introduced":"0"},{"fixed":"3.0.0"}]}]
References
- advisory https://nvd.nist.gov/vuln/detail/CVE-2026-34077
- package https://github.com/remix-run/react-router
- web https://github.com/remix-run/react-router/security/advisories/GHSA-rxv8-25v2-qmq8
- web https://github.com/remix-run/react-router/commit/59811921d3c7d599077b8cadccdcd65a233165e0
- web https://github.com/jacob-ebey/turbo-stream/blob/v2.4.1/src/flatten.ts#L175-L177
- web https://github.com/jacob-ebey/turbo-stream/blob/v2.4.1/src/unflatten.ts#L185-L189
- web https://github.com/advisories/GHSA-rxv8-25v2-qmq8