honojs Hono up to 4.12.33 jsx memo information disclosure

Summaryinfo

A vulnerability classified as problematic was found in honojs Hono up to 4.12.33. This issue affects the function memo of the component jsx. The manipulation results in information disclosure. This vulnerability is reported as CVE-2026-71850. The attack can be launched remotely. No exploit exists.

Detailsinfo

A vulnerability classified as problematic has been found in honojs Hono up to 4.12.33. Affected is the function memo of the component jsx. The manipulation with an unknown input leads to a information disclosure vulnerability. CWE is classifying the issue as CWE-200. The product exposes sensitive information to an actor that is not explicitly authorized to have access to that information. This is going to have an impact on confidentiality. CVE summarizes:

Hono is a Web application framework that provides support for any JavaScript runtime. From 3.8.0 to 4.12.33, memo() from hono/jsx retains the result of a server side render and reuses it for later renders with comparator equal props, and request scoped values read inside the component take no part in that comparison, so a response can contain HTML rendered for another user's request. Components wrapped with memo() are compared by props alone; values read implicitly during rendering, such as JSX Context through createContext() and useContext(), useRequestContext() from hono/jsx-renderer, and getContext() from hono/context-storage, do not participate, and the retained result lives as long as the wrapped component, so it outlives the request that produced it. A user may receive a response containing HTML rendered for another user when both render the same memoized component with comparator equal props on the same warm instance, which may disclose another user's account or profile data, disclose request scoped secrets embedded in HTML such as CSRF tokens, or expose role specific content to users who should not receive it. This issue is fixed in version 4.12.34.

The advisory is shared for download at github.com. This vulnerability is traded as CVE-2026-71850 since 08/07/2026. The exploitability is told to be easy. It is possible to launch the attack remotely. The exploitation doesn't require any form of authentication. There are known technical details, but no exploit is available. The MITRE ATT&CK project declares the attack technique as T1592.

Upgrading to version 4.12.34 eliminates this vulnerability.

VulDB is the best source for vulnerability data and more expert information about this specific topic.

Productinfo

Vendor

• honojs

Name

• Hono

Version

• 4.12.0
• 4.12.1
• 4.12.2
• 4.12.3
• 4.12.4
• 4.12.5
• 4.12.6
• 4.12.7
• 4.12.8
• 4.12.9
• 4.12.10
• 4.12.11
• 4.12.12
• 4.12.13
• 4.12.14
• 4.12.15
• 4.12.16
• 4.12.17
• 4.12.18
• 4.12.19
• 4.12.20
• 4.12.21
• 4.12.22
• 4.12.23
• 4.12.24
• 4.12.25
• 4.12.26
• 4.12.27
• 4.12.28
• 4.12.29
• 4.12.30
• 4.12.31
• 4.12.32
• 4.12.33

Website

• Product: https://github.com/honojs/hono/

CPE 2.3info

• 🔒
• 🔒
• 🔒

CPE 2.2info

• 🔒
• 🔒
• 🔒

CVSSv4info

CVSSv3info

CVSSv2info

Exploitinginfo

Threat Intelligenceinfo

Countermeasuresinfo

Timelineinfo

Sourcesinfo

Entryinfo

VulDB is the best source for vulnerability data and more expert information about this specific topic.

Discussion