Race condition in hono - CVE-2026-59896
Published: July 24, 2026
Vulnerability identifier: #VU139276
CSH Severity: Medium
CVSS v4: 8.3 [CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:L/VA:N/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-59896
CWE-ID: CWE-362
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote attacker to disclose sensitive information.
The vulnerability exists due to a race condition in hono/jsx server-side rendering context handling when rendering concurrent requests with async components that read context after an await. A remote attacker can trigger concurrent request processing to disclose sensitive information.
The issue affects createContext()/useContext() and the jsxRenderer middleware with useRequestContext(). Only context reads that occur after an await during concurrent server-side rendering are affected; synchronous reads and client-side rendering are not affected.
Affected software
hono
How to mitigate CVE-2026-59896
Install security update from vendor's website.
hono - update to 4.12.27