CISA MikroTik RouterOS mitigation guidance for CVE-2026-84411
Advisory/Mitigation
Summary
Hide ▲
Show ▼
CISA issued mitigation guidance for MikroTik RouterOS operators affected by CVE-2026-84411, a pre-authentication integer underflow that can enable root code execution or denial of service. The guidance applies to RouterOS versions below 7.24 and directs administrators toward risk-reduction steps while they update affected systems. CISA said it has no knowledge of active exploitation at this time. Operators are urged to keep control systems off the internet, isolate them behind firewalls, and use updated VPNs for remote access.
Related Happenings
MikroTik RouterOS pre-auth integer underflow (CVE-2026-84411)
Vulnerability
H score1
First: 30.09.2026 18:49
Last: 30.09.2026 18:49
Sources 1
How related:
“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.”
About this happening:
CVE-2026-84411 exposes MikroTik RouterOS management interfaces to unauthenticated root code execution or denial of service through a pre-authentication integer u...
MikroTik RouterOS pre-auth integer underflow (CVE-2026-84411)
VulnerabilityHow related: “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.”
About this happening: CVE-2026-84411 exposes MikroTik RouterOS management interfaces to unauthenticated root code execution or denial of service through a pre-authentication integer u...
WSO2, Adobe Commerce, SharePoint, and RouterOS active exploitation wave
Exploitation Wave
H score34
First: 25.09.2026 20:24
Last: 25.09.2026 20:24
Sources 1
About this happening:
CISA says attackers are actively exploiting four vulnerabilities across WSO2, Adobe Commerce, Microsoft SharePoint, and Mikrotik RouterOS, creating a broad...
WSO2, Adobe Commerce, SharePoint, and RouterOS active exploitation wave
Exploitation WaveAbout this happening: CISA says attackers are actively exploiting four vulnerabilities across WSO2, Adobe Commerce, Microsoft SharePoint, and Mikrotik RouterOS, creating a broad...
MikroTik RouterOS SSH exploitation wave
Exploitation Wave
H score8
First: 06.09.2026 12:32
Last: 06.09.2026 12:32
Sources 1
About this happening:
MikroTik RouterOS SSH exploitation is using the MikroTrick chain, where CVE-2026-67279 and CVE-2026-86060 combine to give attackers full administrative control...
MikroTik RouterOS SSH exploitation wave
Exploitation WaveAbout this happening: MikroTik RouterOS SSH exploitation is using the MikroTrick chain, where CVE-2026-67279 and CVE-2026-86060 combine to give attackers full administrative control...
Latest development: 23.09.2026 19:06
CERT Polska details the MikroTrick chain on MikroTik RouterOS SSH, combining CVE-2026-67279 with CVE-2026-86060 to let attackers reach full administrative control on Internet-exposed routers without a password or SSH key. Attack logs date to at least September 2, CISA added CVE-2026-86060 to its Known Exploited Vulnerabilities catalog on September 10, and CERT Polska says some writeups incorrectly included CVE-2026-67276.
Citrix NetScaler ADC/Gateway memory overflow flaw (CVE-2026-8452)
Vulnerability
H score34
First: 27.08.2026 12:16
Last: 27.08.2026 12:16
Sources 1
About this happening:
CVE-2026-8452 is an actively exploited memory overflow flaw in Citrix NetScaler ADC and NetScaler Gateway appliances, including systems configured with Gateway V...
Citrix NetScaler ADC/Gateway memory overflow flaw (CVE-2026-8452)
VulnerabilityAbout this happening: CVE-2026-8452 is an actively exploited memory overflow flaw in Citrix NetScaler ADC and NetScaler Gateway appliances, including systems configured with Gateway V...
CISA-led joint advisory to secure internet-exposed ATG systems
Public Sector Action
H score43
First: 05.06.2026 17:50
Last: 05.06.2026 17:50
Sources 1
About this happening:
On 2026-06-05, CISA, the FBI, the NSA, the Department of Energy, and other U.S. partners issued a joint advisory telling critical infrastructure organiza...
CISA-led joint advisory to secure internet-exposed ATG systems
Public Sector ActionAbout this happening: On 2026-06-05, CISA, the FBI, the NSA, the Department of Energy, and other U.S. partners issued a joint advisory telling critical infrastructure organiza...
Timeline
-
30.09.2026 18:49 2 articles · 1h ago
CISA warns of critical pre-authentication flaw in MikroTik RouterOS
Initial DisclosureCISA warned that MikroTik RouterOS contains CVE-2026-84411, a pre-authentication integer underflow in web-management HTTP request body handling that could let an unauthenticated network attacker achieve arbitrary code execution as root or trigger a denial of service with a single crafted request. CISA said it has no knowledge of active exploitation and issued defensive guidance for MikroTik router owners to keep control systems off the internet, place control networks and remote devices behind firewalls and away from business networks, use updated VPNs for remote access, and secure all connected devices, while noting that RouterOS versions below 7.24 are affected.
Show sources
- CISA warns of critical pre-auth RCE flaw in MikroTik RouterOS — www.bleepingcomputer.com — 30.09.2026 18:49
- CISA warns of critical pre-auth RCE flaw in MikroTik RouterOS — www.bleepingcomputer.com — 30.09.2026 18:49