Critical 9.8Published Oct 2, 2026

CVE-2026-84411MikroTik RouterOS Integer Underflow

Updated under an hour ago (2026-10-19 05:50 UTC)

Does this affect you?

It affects MikroTik RouterOS. Add what you run to find out whether that includes you.

EPSS puts the chance of exploitation in the next 30 days at 0.95%, higher than 60% of scored CVEs.

Do this next

Start free and add your stack

Free account, 1 product

Every CVE for MikroTik RouterOS

Exploited in the last 30 days

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.

CVSS: 9.8 CRITICAL (v3.1, CNA)CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Weakness (CWE): CWE-191
Known exploited: Not in CISA's KEV catalog
EPSS (exploitation in the next 30 days): 0.95% (percentile 60)
Assigned by: icscert
NVD analysis: Awaiting Analysis
Record last updated: Oct 3, 2026
First seen by InfoSec Signals: Oct 9, 2026

Affected products

Affected products

MikroTik RouterOS mikrotik:routeros (from the name)	before 7.24; 7.24 not affected	CNA record

References

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

The CVE record on cve.org NVD's entry

The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.