CVE-2026-54609
HIGHCVE-2026-54609 is a high-severity (CVSS 8.6) Uncontrolled Resource Consumption vulnerability in com.quietterminal:qti-neon. O3 Security confirms whether CVE-2026-54609 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
QTINeon has unauthenticated relay-to-host amplification via unbounded RECONNECT_REQUEST forwarding
Blast Radius
com.quietterminal:qti-neon📦qti-neon🐍qti-neonReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects Maven, npm, PyPI packages — download data is not available via public APIs for these ecosystems.
Description
QTI Neon is a minimal, game-agnostic, relay-based UDP multiplayer protocol library. In version 1.0.0, the relay's handleReconnectRequest forwards RECONNECT_REQUEST packets to the host without bounding them, so an unauthenticated client can drive relay-to-host amplification and cause a denial of service on the host. No fixed version is available as of this review.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| ☕Maven | com.quietterminal:qti-neon | all versions | No fix |
| 📦npm | qti-neon | all versions | No fix |
| 🐍PyPI | qti-neon | all versions | No fix |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for com.quietterminal:qti-neon. 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.
Remediation status
No patched version of com.quietterminal:qti-neon has shipped for CVE-2026-54609 yet. Where your build allows, override or pin the dependency away from the vulnerable range, and apply any maintainer-recommended mitigation.
Mitigate without a patch
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-2026-54609 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-2026-54609. 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-2026-54609 in your dependencies?
O3 detects CVE-2026-54609 across Maven, npm, PyPI dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.