CISA has warned about CVE-2026-84411, a critical pre-authentication integer underflow in MikroTik RouterOS that can allow unauthenticated attackers to execute code as root or trigger a denial of service with a single crafted request. The agency says no active exploitation is known yet, but it urges MikroTik router owners to restrict internet exposure, segment networks, and update affected systems. #CVE-2026-84411 #MikroTik #RouterOS
Keypoints
- CISA warned of CVE-2026-84411 in MikroTik RouterOS.
- The flaw is a pre-authentication integer underflow in web-management HTTP request handling.
- A single crafted request can enable root code execution or cause a denial of service.
- Versions below RouterOS 7.24 are affected, according to CISA.
- CISA advises isolating control systems, using firewalls, and securing remote access with updated VPNs.