Open Redirect in react-router (CVE-2026-40181)
Summary
Vulnerability in react-router (CVE-2026-40181). Risk of unauthorized operations or information disclosure. Exploitable via redirect. Mitigation: upgrade to 6.30.4 or later.
Original description
The description as published by the source.
Certain URLs passed to the redirect function can trigger an open redirect to an external domain depending on the level of validation done by the application prior to returning the redirect.
[!NOTE]
This does not impact your React Router application if you are using Declarative Mode (``)
Source: NIST National Vulnerability Database 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-2026-40181 has been found in react-router.
Attackers can target a specific entry point like redirect over the network to misuse the product.
Risk of unauthorized operations or information disclosure. CVSS score: 6.1/10.
What to do: upgrade react-router to 6.30.4 or later.
If unsure, ask your IT team or search "react-router CVE-2026-40181" on the vendor's site.
CVE-2026-40181 (react-router) — CWE-601 / CVSS v3 6.1
Attack vector: remote (network-reachable) / unauthenticated
Attack surface: redirect
Patched: 6.30.4 — 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.
A vulnerability (CWE-601) exists in react-router. Attackers reach the vulnerable code path via redirect without authentication.
Check the vendor advisory for the affected versions of react-router. Attack surface: redirect.
Severity: Medium (CVSS 6.1/10). Risk of unauthorized operations or information disclosure.
Update to 6.30.4.
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 'react-router' . 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 '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。 -
2Apply patch patch
Upgrade react-router to 6.30.4ステージング環境で 6.30.4 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。
-
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。
Affected packages
References
- package github.com
- patch security-advisories@github.com
- web nvd.nist.gov
- web github.com
- web github.com