medium

CVE-2026-59896

npm · hono

Summary

hono/jsx does not isolate context per request, leading to cross-request data disclosure

Severity
medium
CVSS
6.5
EPSS
0.3% (p22)
CWE
CWE-362
Also known as
GHSA-hvrm-45r6-mjfj
Published
2026-07-21
Updated
2026-07-21

Advisory details

Summary

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.

Details

During 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.

This affects the usual ways request-scoped data is passed through a server-rendered JSX tree:

It 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.

Impact

Under 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.

This may lead to:

References

Related advisories

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Sources: CISA KEV (public domain), OSV.dev & GitHub Advisory Database (CC-BY-4.0), FIRST EPSS, NVD/CWE (public domain). Served live from the Stateward advisory database.