CVE-2026-90690 is a high-severity (CVSS 7.3) CWE-77 vulnerability in 0x4m4 hexstrike ai. O3 Security detects and blocks CVE-2026-90690 exploitation at runtime via eBPF exploit-chain detection and L7 egress monitoring, even on unpatched systems.
A weakness has been identified in 0x4m4 HexStrike AI up to d689933ff579d839c676c82b231f8e98326c5f04. The affected element is the function subprocess.Popen of the file hexstrike_server.py…
Description
A weakness has been identified in 0x4m4 HexStrike AI up to d689933ff579d839c676c82b231f8e98326c5f04. The affected element is the function subprocess.Popen of the file hexstrike_server.py of the component API Tools Endpoint. Executing a manipulation of the argument additional_args/target/username/password/scan_type/payload can lead to os command injection. The attack can be launched remotely. The exploit has been made available to the public and could be used for attacks. This product does not use versioning. This is why information about affected and unaffected releases are unavailable. A fix appears to be in progress.
Affected Products
hexstrike ai0x4m4Detection & mitigation playbook
Vendor / applianceDetect
Inventory every 0x4m4 hexstrike ai 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 remote code execution at the network and runtime layer — O3 flags the exploit behaviour from runtime telemetry and egress traffic even before a vulnerable build is confirmed.
Remediation status
No patch has shipped for CVE-2026-90690 yet — track the 0x4m4 hexstrike ai advisory for a fixed release and apply the workarounds below in the meantime.
Mitigate without a patch
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-2026-90690 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-2026-90690. 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-2026-90690 being exploited in your environment?
O3's eBPF runtime sensors and L7 egress monitoring detect and block the CVE-2026-90690 exploit chain at execution — protecting unpatched and end-of-life systems until the vendor patch is applied.