{"id":"GHSA-rxv8-25v2-qmq8","summary":"React Router vulnerable to Denial of Service via reflected user input in single-fetch","details":"A DoS vulnerability exists in the React Router v7 [Framework Mode](https://reactrouter.com/start/modes#framework), as well as Remix v2.9.0+ with [Single Fetch](https://v2.remix.run/docs/guides/single-fetch) enabled. In some scenarios the underlying serialization algorithm can become a bottleneck when encoding specific types of data into server responses.  Please upgrade to React Router v7.14.0 or later.\n\n\u003e [!NOTE]\n\u003e This does not impact your React Router application if you are using [Declarative Mode](https://reactrouter.com/start/modes#declarative) (`\u003cBrowserRouter\u003e`) or [Data Mode](https://reactrouter.com/start/modes#data) (`createBrowserRouter`/`\u003cRouterProvider\u003e`).","aliases":["CVE-2026-34077"],"modified":"2026-06-04T15:30:15.321859530Z","published":"2026-06-04T15:23:51Z","database_specific":{"cwe_ids":["CWE-770"],"severity":"HIGH","github_reviewed":true,"github_reviewed_at":"2026-06-04T15:23:51Z","nvd_published_at":"2026-06-02T20:16:34Z"},"references":[{"type":"WEB","url":"https://github.com/remix-run/react-router/security/advisories/GHSA-rxv8-25v2-qmq8"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-34077"},{"type":"WEB","url":"https://github.com/remix-run/react-router/commit/59811921d3c7d599077b8cadccdcd65a233165e0"},{"type":"WEB","url":"https://github.com/jacob-ebey/turbo-stream/blob/v2.4.1/src/flatten.ts#L175-L177"},{"type":"WEB","url":"https://github.com/jacob-ebey/turbo-stream/blob/v2.4.1/src/unflatten.ts#L185-L189"},{"type":"PACKAGE","url":"https://github.com/remix-run/react-router"}],"affected":[{"package":{"name":"react-router","ecosystem":"npm","purl":"pkg:npm/react-router"},"ranges":[{"type":"SEMVER","events":[{"introduced":"7.0.0"},{"fixed":"7.14.0"}]}],"database_specific":{"source":"https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/06/GHSA-rxv8-25v2-qmq8/GHSA-rxv8-25v2-qmq8.json"}},{"package":{"name":"turbo-stream","ecosystem":"npm","purl":"pkg:npm/turbo-stream"},"ranges":[{"type":"SEMVER","events":[{"introduced":"0"},{"fixed":"3.0.0"}]}],"database_specific":{"source":"https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/06/GHSA-rxv8-25v2-qmq8/GHSA-rxv8-25v2-qmq8.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"}]}