CVE-2026-59896 honojs CVE debrief

Who should care

Users of Hono framework versions between 4.11.8 and 4.12.26 should update to version 4.12.27 to address this vulnerability. Operators, platform administrators, vulnerability management teams, and security teams should review the official advisory and CVE record to validate affected scope, severity, and vendor guidance. They should also plan vendor-supported updates or mitigations through normal change control where exposure is confirmed.

Technical summary

The Hono framework's jsx feature did not properly isolate context values per request during server-side rendering. This could allow data from a different in-flight request to be used after an await in an async component, potentially leading to security issues. The vulnerability has a CVSS score of 6.5 and is classified as MEDIUM severity. It affects Hono framework versions between 4.11.8 and 4.12.26. The issue is fixed in version 4.12.27. Users should review async components using createContext, useContext, jsxRenderer, or useRequestContext and monitor for potential security issues related to server-side rendering.

Defensive priority

Medium priority, as the vulnerability requires specific conditions to be exploited and has a moderate CVSS score.

Recommended defensive actions

• Update Hono framework to version 4.12.27 or later
• Review async components using createContext, useContext, jsxRenderer, or useRequestContext
• Monitor for potential security issues related to server-side rendering
• Confirm whether affected product deployments exist in managed environments and assign an owner for follow-up
• Review compensating controls for exposed systems while remediation is scheduled and verified
• Check relevant monitoring, detection, and logs for exposed assets that need extra review
• Track exceptions, retest remediated assets, and close the item only after evidence is documented

Evidence notes

The CVE record was published on 2026-07-08T17:17:27.493Z and last modified on 2026-07-10T18:01:31.563Z. The NVD entry is currently awaiting analysis. There is limited information available about the vulnerability, and defenders should verify the affected scope and severity with the vendor. The Hono framework's jsx feature did not properly isolate context values per request during server-side rendering, potentially leading to security issues. Users should review the official advisory and CVE record for more information.

Sources and references

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.