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Actively exploited

CVE-2018-7445 MikroTik RouterOS Stack-Based Buffer Overflow Vulnerability

In MikroTik RouterOS, a stack-based buffer overflow occurs when processing NetBIOS session request messages. Remote attackers with access to the service can exploit this vulnerability and gain code execution on the system.

From the CISA KEV catalogue version 2026.11.06, with Cybergen analysis. Updated 6 Nov 2026.

Our Assessment

Should You Worry?

Patch nowCybergen assessment
  • CISA confirmed exploitation in the wild and added it to the Known Exploited Vulnerabilities catalogue on 8 Sep 2022.
  • Rated Critical severity (CVSS 9.8, scored by CISA).
  • It has been in the catalogue for 1,520 days. Systems still unpatched now have almost certainly been scanned for it.
The Vulnerability

What It Is

A buffer overflow was found in the MikroTik RouterOS SMB service when processing NetBIOS session request messages. Remote attackers with access to the service can exploit this vulnerability and gain code execution on the system. The overflow occurs before authentication takes place, so it is possible for an unauthenticated remote attacker to exploit it. All architectures and all devices running RouterOS before versions 6.41.3/6.42rc27 are vulnerable.

From Watch to Action

What To Do Now

  1. 1

    Find it

    Search your asset inventory and external attack surface for MikroTik RouterOS. Include cloud images, appliances and anything a supplier runs for you.

    Attack Surface Management
  2. 2

    Fix it

    Apply updates per vendor instructions.

    Vulnerability Management
  3. 3

    Hunt for compromise

    If an affected system was reachable before you patched, assume it may have been hit. Check logs, new accounts, web shells and outbound connections from the date of exposure.

    Incident Response
  4. 4

    Prove it is fixed

    Rescan or test the system after patching. Upgrades that fail silently and forgotten secondary instances are common.

    Penetration Testing

Vendor Advisories

Regulation

The Compliance Clock

Cyber EssentialsRated critical, so if it affects devices in your Cyber Essentials scope, the update must be installed within 14 days of the vendor releasing it.NIS2If exploitation causes a significant incident, essential and important entities owe their CSIRT an early warning within 24 hours and a notification within 72 hours.DORAFinancial entities must classify ICT incidents and send an initial notification for a major incident within strict deadlines, with exploited flaws a common cause.US federal (BOD 22-01)Federal civilian agencies had until 29 Sep 2022 to remediate. A sensible benchmark for everyone else.

General guidance, not legal advice. Your obligations depend on your sector, scope and jurisdiction.

Stay Ahead

More Exploited MikroTik Flaws

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CVE-2026-67279Mikrotik RouterOS Improper Enforcement of Behavioral Workflow VulnerabilityAdded 25 Sep 2026CVE-2026-86060MikroTik RouterOS Improper Neutralization of Argument Delimiters in a Command VulnerabilityAdded 10 Sep 2026CVE-2026-67277MikroTik RouterOS Missing Authentication for Critical Function VulnerabilityAdded 10 Sep 2026CVE-2018-14847MikroTik Router OS Directory Traversal VulnerabilityAdded 1 Dec 2021

All 5 exploited MikroTik vulnerabilities

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Evidence

Sources

  1. CISA Known Exploited Vulnerabilities catalogue
  2. NVD: CVE-2018-7445
  3. CVE record: CVE-2018-7445
  4. FIRST EPSS
  5. coresecurity.com/core-labs/advisories/mikrotik-routeros-smb-buffer-overflow#vendor_update, https://m
  6. securityfocus.com/bid/103427
  7. seclists.org/fulldisclosure/2018/Mar/38
  8. exploit-db.com/exploits/44290/
  9. coresecurity.com/advisories/mikrotik-routeros-smb-buffer-overflow