CVE-2026-40181

React Router's same-origin redirect with path starting // causes open redirect via protocol-relative URL reinterpretation

MEDIUM
6.1
CVSS Score
Published: June 2, 2026 at 05:55 PM UTC
Updated: August 4, 2026 at 10:17 PM UTC
3 products affected across 2 vendorsReact RouterReact RouterRouter

Using react-router by remix-run?

Get instant alerts when new vulnerabilities affect react-router - before attackers find them.

Real-time alertsTrack your software stackFree plan available
Severity
MEDIUM6.1
Exploit prediction
EPSS 0.2%
SSVC
No known exploit

Description

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 reinterpreted as protocol-relative URLs. The level of impact depends on the validation done by the application prior to returning the redirect. This does not impact applications using Declarative Mode (<BrowserRouter>). This is patched in versions 7.14.1 and 6.30.4.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

6.7.0 ≤ v < 6.30.47.0.0 ≤ v < 7.14.1
Affected range stops below 6.30.4, so it looks safe — our inference, not a vendor statement
Affected range stops below 7.14.1, so it looks safe — our inference, not a vendor statement
v < 6.30.4v < 7.14.1
Affected range stops below 6.30.4, so it looks safe — our inference, not a vendor statement
Affected range stops below 7.14.1, so it looks safe — our inference, not a vendor statement
v < 1.23.3
Affected range stops below 1.23.3, so it looks safe — our inference, not a vendor statement

Remediation

No guide yet

No remediation guidance has been written for this CVE yet. What the record does show:

References (1)

SSVC — Action Prioritization

SSVCNo known exploitAutomatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

Attack Vector
NETWORK
Complexity
LOW
Privileges
NONE
User Interaction
REQUIRED
Scope
CHANGED
Confidentiality
LOW
Integrity
LOW
Availability
NONE
Vector?

Quick Info

StatusANALYZED
CWE
CWE-601

Get alerted

Stop reading CVE feeds looking for your own stack

Track the products you run and VulnTracker tells you when a new CVE affects them — with what is known about fixing it, and nothing about the rest.

Free plan, no card