What’s Vulnerable › Vulnerabilities

CVE-2026-84411: MikroTik RouterOS Integer Underflow

• Severity: critical (CVSS 9.8 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.9% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-10-02 · updated 2026-10-06
• Weakness: CWE-191

Description

The web management service in affected RouterOS versions contains an integer underflow in its HTTP request body handling that is reachable before authentication. This can be leveraged by an unauthenticated network attacker to achieve arbitrary code execution as root, or to cause a denial of service, using a single crafted request.

Affected products

• MikroTik RouterOS: before 7.24 — fixed in 7.24

How to fix

Upgrade to a fixed version: MikroTik RouterOS 7.24. Check the vendor advisory for mitigations.

References

• https://github.com/cisagov/CSAF/blob/develop/csaf_files/OT/white/2026/icsa-26-272-06.json
• https://mikrotik.com/download
• https://www.cisa.gov/news-events/ics-advisories/icsa-26-272-06

Get alerted when CVE-2026-84411 or the next vulnerability affects your stack