What is CVE-2026-40181?

CVE-2026-40181 is a medium-severity vulnerability in Remix-run React-router, classified under URL Redirection to Untrusted Site (Open Redirect). CVSS score: 6.1/10. Published 2026-06-02.

How severe is CVE-2026-40181?

Medium severity. CVSS v3 base score is 6.1 out of 10.

Open Redirect in Remix-run React-router

CVE-2026-40181

React Router is a router for React. In versions 7.0.0 through 7.14.0 and 6.7.0 through 6.30.3, certain URLs passed to the redirect function can trigger an open redirect to an external domain due to path values starting with // being reinte…

Vulnerability class: Open Redirect

EPSS: 0.000 (12.7th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 6.1 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N.

Affected products

Remix-run React-router — versions >= 7.0.0, < 7.14.1, >= 6.7.0, < 6.30.4
Shopify React-router

Weakness classification (CWE)

CWE-601 — URL Redirection to Untrusted Site (Open Redirect)

References

security-advisories@github.com (x_refsource_CONFIRM, Vendor Advisory)

Frequently asked questions

What is CVE-2026-40181?: CVE-2026-40181 is a medium-severity vulnerability in Remix-run React-router, classified under URL Redirection to Untrusted Site (Open Redirect). CVSS score: 6.1/10. Published 2026-06-02.
How severe is CVE-2026-40181?: Medium severity. CVSS v3 base score is 6.1 out of 10.