CVE-2026-44459
LOWHono is a Web application framework that provides support for any JavaScript runtime. Prior to 4.12.18, improper validation of the JWT NumericDate claims exp, nbf, and iat in hono/utils/jwt…
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.
Description
Hono is a Web application framework that provides support for any JavaScript runtime. Prior to 4.12.18, improper validation of the JWT NumericDate claims exp, nbf, and iat in hono/utils/jwt allows tokens with non-spec-compliant claim values to silently bypass time-based checks. This issue is not exploitable by an anonymous attacker; it only manifests when a malformed claim value reaches verify() — typically when the application itself issues such tokens, or when the signing key is otherwise under attacker control. This vulnerability is fixed in 4.12.18.
Affected Products
honohonoDetection & mitigation playbook
Vendor / applianceDetect
Inventory every hono hono deployment and check each version against the affected-products list above. Because the exploit targets the running system rather than your application code, also watch for exploitation at the network and runtime layer — O3 flags the exploit behaviour from runtime telemetry and egress traffic even before a vulnerable build is confirmed.
Fix
Apply the hono hono security patch or hotfix for CVE-2026-44459 on the affected version, following the vendor advisory for your exact build.
Workarounds
Cut exposure now: restrict the management/admin interface to trusted networks, segment the device, and apply the vendor's recommended configuration mitigations and any WAF/IPS signature. O3's runtime protection blocks the exploit chain at execution, holding the line on unpatched or end-of-life systems until you can patch.
How O3 protects you
O3 detects and blocks CVE-2026-44459 exploitation at runtime: eBPF exploit-chain detection, plus L7 egress monitoring that catches the post-exploitation callback and severs the attacker's outbound channel.
Tailored to CVE-2026-44459. 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-2026-44459 being exploited in your environment?
O3's eBPF runtime sensors and L7 egress monitoring detect and block the CVE-2026-44459 exploit chain at execution — protecting unpatched and end-of-life systems until the vendor patch is applied.