CVE-2026-84411

critical

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.

References

References
More

https://www.databreachtoday.com/breach-roundup-cisco-sd-wan-flaw-under-attack-a-33001

https://www.bleepingcomputer.com/news/security/cisa-warns-of-critical-pre-auth-rce-flaw-in-mikrotik-routeros/

https://www.cisa.gov/news-events/ics-advisories/icsa-26-272-06

https://mikrotik.com/download

https://github.com/cisagov/CSAF/blob/develop/csaf_files/OT/white/2026/icsa-26-272-06.json

Details

Source: Mitre, NVD

Published: 2026-10-02

Updated: 2026-10-02

Risk Information

CVSS v2

Base Score: 10

Vector: CVSS2#AV:N/AC:L/Au:N/C:C/I:C/A:C

Severity: Critical

CVSS v3

Base Score: 9.8

Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Severity: Critical

CVSS v4

Base Score: 9.3

Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N

Severity: Critical