{"id":"GHSA-hvrm-45r6-mjfj","summary":"hono/jsx does not isolate context per request, leading to cross-request data disclosure","details":"### Summary\n\n`hono/jsx` did not isolate context values per request during server-side rendering. While an async component was suspended on `await`, its provided context value stayed observable to other requests rendering concurrently, so `useContext()` could return a value from a different in-flight request.\n\n### Details\n\nDuring server-side rendering, context values were kept in a process-wide structure rather than scoped to each request's render. While an async component awaited, another request entering the same provider could observe or replace the value; when the first render resumed, it could read the other request's context.\n\nThis affects the usual ways request-scoped data is passed through a server-rendered JSX tree:\n\n- `createContext()` / `useContext()`\n- the `jsxRenderer` middleware and `useRequestContext()`\n\nIt arises only when context is read after an `await` inside an async component while requests render concurrently. Reading context synchronously (before any `await`), purely synchronous rendering, and client-side (DOM) rendering are not affected.\n\n### Impact\n\nUnder concurrent requests, a response could be rendered with another request's context. A user may receive HTML rendered for a different user, and an authorization check performed after an `await` may be evaluated against another user's data.\n\nThis may lead to:\n\n- disclosure of rendered output intended for another user\n- authorization decisions made with the wrong request's context\n- cross-request mixing of session or other request-scoped state","aliases":["CVE-2026-59896"],"modified":"2026-07-21T18:45:58.568400911Z","published":"2026-07-21T18:34:19Z","database_specific":{"cwe_ids":["CWE-362"],"severity":"MODERATE","github_reviewed":true,"github_reviewed_at":"2026-07-21T18:34:19Z","nvd_published_at":"2026-07-08T17:17:27Z"},"references":[{"type":"WEB","url":"https://github.com/honojs/hono/security/advisories/GHSA-hvrm-45r6-mjfj"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-59896"},{"type":"WEB","url":"https://github.com/honojs/hono/commit/fab3b13639339cbd5ba1166a5b23d9ac30c5f64f"},{"type":"PACKAGE","url":"https://github.com/honojs/hono"},{"type":"WEB","url":"https://github.com/honojs/hono/releases/tag/v4.12.27"}],"affected":[{"package":{"name":"hono","ecosystem":"npm","purl":"pkg:npm/hono"},"ranges":[{"type":"SEMVER","events":[{"introduced":"4.11.8"},{"fixed":"4.12.27"}]}],"database_specific":{"source":"https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/07/GHSA-hvrm-45r6-mjfj/GHSA-hvrm-45r6-mjfj.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:L/A:N"}]}