How severe is GHSA-458j-xx4x-4375?

GHSA-458j-xx4x-4375 has a CVSS score of 4.3/10, rated MEDIUM. Review your exposure and patch according to your risk tolerance.

Which packages are affected by GHSA-458j-xx4x-4375?

GHSA-458j-xx4x-4375 affects the following packages: hono (npm). Ecosystems affected: npm.

How do I fix GHSA-458j-xx4x-4375?

Update hono to 4.12.14 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-458j-xx4x-4375 is resolved across your whole dependency graph.

How do I detect GHSA-458j-xx4x-4375 in my npm dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for hono. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.

How do I mitigate GHSA-458j-xx4x-4375 if there is no patch (or I can't update yet)?

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 does O3 Security protect against GHSA-458j-xx4x-4375?

O3 pinpoints whether GHSA-458j-xx4x-4375 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.

Is GHSA-458j-xx4x-4375 actively exploited in the wild?

No public exploit code has been indexed for GHSA-458j-xx4x-4375 yet. This does not mean the vulnerability cannot be exploited — absence of public exploits does not imply safety. Apply the recommended fix and use O3 Security to monitor your exposure.

When was GHSA-458j-xx4x-4375 published, and has it been updated?

GHSA-458j-xx4x-4375 was published on April 16, 2026 and was last updated on April 16, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

📦 npm

GHSA-458j-xx4x-4375

MEDIUM

hono Improperly Handles JSX Attribute Names Allows HTML Injection in hono/jsx SSR

Published

Apr 16, 2026

Updated

Apr 16, 2026

Affected

1 pkg

Patched

1 / 1

Exploits

None indexed

Blast Radius

1 pkg affected

Weekly download volume for affected packages — a proxy for how broadly this vulnerability is deployed.

hononpm

49.8Mdownloads / week

Description

Summary

Improper handling of JSX attribute names in hono/jsx allows malformed attribute keys to corrupt the generated HTML output.

When untrusted input is used as attribute keys during server-side rendering, specially crafted keys can break out of attribute or tag boundaries and inject unintended HTML.

Details

When rendering JSX elements to HTML strings, attribute values are escaped, but attribute names (keys) were previously inserted into the output without validation.

If an attribute name contains characters such as ", >, or whitespace, it can alter the structure of the generated HTML.

For example, malformed attribute names can:

Break out of the current attribute and introduce unintended additional attributes
Break out of the current HTML tag and inject new elements into the output

This issue arises when untrusted input (such as query parameters or form data) is used as JSX attribute keys during server-side rendering.

Impact

An attacker who can control attribute keys used in JSX rendering may inject unintended attributes or HTML elements into the generated output.

This may lead to:

Injection of unexpected HTML attributes
Corruption of the HTML structure
Potential cross-site scripting (XSS) if combined with unsafe usage patterns

This issue affects applications that pass untrusted input as JSX attribute keys during server-side rendering.

Affected Packages

1 total 1 fixed

Ecosystem	Package	Vulnerable range	Fix
📦npm	`hono`	all versions	4.12.14

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for hono. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Fix
Update hono to 4.12.14 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-458j-xx4x-4375 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 pinpoints whether GHSA-458j-xx4x-4375 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.

Tailored to GHSA-458j-xx4x-4375. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.

Frequently Asked Questions

## Summary Improper handling of JSX attribute names in hono/jsx allows malformed attribute keys to corrupt the generated HTML output. When untrusted input is used as attribute keys during server-side rendering, specially crafted keys can break out of attribute or tag boundaries and inject unintended HTML. ## Details When rendering JSX elements to HTML strings, attribute values are escaped, but attribute names (keys) were previously inserted into the output without validation. If an attribute name contains characters such as `"`, `>`, or whitespace, it can alter the structure of the genera

O3 Security · Impact-Aware SCA

Is GHSA-458j-xx4x-4375 in your dependencies?

O3 detects GHSA-458j-xx4x-4375 across npm dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.

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