GHSA-f23p-vx2j-j53r is a medium-severity (CVSS 4.8) CWE-488 vulnerability in hono. A fix is available for hono — see the affected versions and patch details below.
Hono: `memo()` retains SSR output across requests, leading to cross-user data disclosure
Exploitation Status
No confirmed exploitation observed yet
- CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.
Exploitation and automatability from CISA’s SSVC triage for GHSA-f23p-vx2j-j53r.
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
How urgent is this, really
GHSA-f23p-vx2j-j53r plotted by exploitation likelihood (EPSS) against impact (CVSS). The shaded corner — EPSS 50%+ and CVSS 7.0+ — is where this CVE doesn't sit, though severity or exploitability alone can still warrant action.
Where this sits among everything scored
Of 377,636 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Real counts from FIRST.org, not a sample — log-scaled since the landscape is heavily right-skewed.
Real-World Exposure
How broadly this vulnerability is actually deployed: weekly install volume shows current usage, and reverse-dependency count shows how many other packages break if it stays unpatched.
hononpmDescription
Summary
memo() from hono/jsx retains the result of a server-side render and reuses it for later renders with comparator-equal props. 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.
Details
Components wrapped with memo() are compared by props alone. Values read implicitly during rendering do not participate: JSX Context through createContext() and useContext(), useRequestContext() from hono/jsx-renderer, and getContext() from hono/context-storage. The retained result lives as long as the wrapped component, so it outlives the request that produced it.
Per-request context isolation is not what fails: the current request's values are established correctly, but the memoized component is skipped before anything reads them.
This issue arises when a component wrapped in memo() obtains user- or request-specific data from an ambient context instead of through props.
Impact
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.
This may lead to:
- Disclosure of another user's account or profile data
- Disclosure of request-scoped secrets embedded in HTML, such as CSRF tokens
- Exposure of role-specific content to users who should not receive it
Exploitation depends on the order in which renders populate the retained value and on both requests reaching the same warm instance.
This issue affects applications that render with hono/jsx on the server and wrap a component reading ambient request state in memo(). Applications that pass all request-specific values through props, or that do not use memo(), are unaffected. Client-side rendering is unaffected.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | hono | ≥ 3.8.0&&< 4.12.34 | 4.12.34npm install hono@4.12.34 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for hono, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update hono to 4.12.34 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-f23p-vx2j-j53r is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like GHSA-f23p-vx2j-j53r can be triaged on real exposure rather than presence alone.
Tailored to GHSA-f23p-vx2j-j53r. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is GHSA-f23p-vx2j-j53r in your dependencies?
O3 Security finds GHSA-f23p-vx2j-j53r across npm dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.