CVE-2026-44455
MEDIUMCVE-2026-44455 is a medium-severity (CVSS 4.7) vulnerability in hono. O3 Security confirms whether CVE-2026-44455 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
Hono: Unvalidated JSX Tag Names in hono/jsx May Allow HTML Injection
Blast Radius
Weekly download volume for affected packages — a proxy for how broadly this vulnerability is deployed.
hononpmDescription
Hono is a Web application framework that provides support for any JavaScript runtime. Prior to 4.12.16, Improper handling of JSX element tag names in hono/jsx allowed unvalidated tag names to be directly inserted into the generated HTML output. When untrusted input is used as a tag name via the programmatic jsx() or createElement() APIs during server-side rendering, specially crafted values may break out of the intended element context and inject unintended HTML. This vulnerability is fixed in 4.12.16.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | hono | all versions | 4.12.16 |
Detection & mitigation playbook
Open-source dependencyDetect
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 4.12.16 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-44455 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 CVE-2026-44455 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 CVE-2026-44455. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2026-44455 in your dependencies?
O3 detects CVE-2026-44455 across npm dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.