GHSA-337j-9hxr-rhxg

    Dashboard / Vulnerabilities / GHSA-337j-9hxr-rhxg

    GHSA-337j-9hxr-rhxg

    Published: 23 Jul 2026Last Modified: 10 Sept 2026

    Summary: React Router: Arbitrary Constructor Injection via deserializeErrors() in React Router SSR Hydration

    Details: If application code allows attacker supplied input to overwrite certain aspects of errors caught by the SSR process, then it was possible for attacker to trigger unexpected constructor execution on the client which would trigger outbound network traffic. This is only possible with very specific (and unlikely) application layer code. > [!NOTE] > This does not impact your application if you are using Declarative Mode. This only impacts Framework Mode and Data Mode applications doing manual SSR/hydration

    References: https://github.com/remix-run/react-router/security/advisories/GHSA-337j-9hxr-rhxg, https://github.com/remix-run/react-router/pull/15175, https://github.com/remix-run/react-router/commit/9d22943fd46c8ae4b08236425fa3549e10e9ad1a, https://github.com/remix-run/react-router, https://github.com/remix-run/react-router/blob/main/CHANGELOG.md#v7180, https://github.com/remix-run/react-router/releases/tag/[email protected]

    Affected packages

    Package

    Name: react-router

    Purl: pkg:npm/react-router

    Affected ranges

    Type: SEMVER

    Events:

    Introduced- 6.4.0
    Fixed -7.18.0

    Affected versions

    Common Vulnerability Scoring System

    Attack Vector
    Network
    Adjacent
    Local
    Physical
    Privileges Required
    None
    Low
    High
    User Interaction
    None
    Required
    Scope
    Unchanged
    Changed
    Confidentiality
    None
    Low
    High
    Integrity
    None
    Low
    High
    Availability
    None
    Low
    High
    GHSA-337j-9hxr-rhxg | CVE-DB