CVE-2026-67277

MikroTik RouterOS authentication bypass, confirmed exploited in the wild.

MikroTik RouterOS contains a missing authentication for critical function vulnerability which allows kernel memory disclosure and denial of service in the btest service.

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1.6%chance of exploitation in the next 30 days (EPSS), 75th percentile

10 Sepadded to CISA's Known Exploited Vulnerabilities list, 2026

13 Sepfederal remediation deadline, already passed

Passedpast the deadline: patch now

CISA's name for it	MikroTik RouterOS Missing Authentication for Critical Function Vulnerability
Vendor and product	MikroTik · RouterOS
Type	authentication bypass · CWE-306
Exploited	Confirmed by CISA listed 10 September 2026
Likelihood	more likely to be exploited than most
Deadline	13 September 2026 · already passed
Used in ransomware	Not reported
Advisories	mikrotik.com ↗ · www.cisa.gov ↗ · www.cisa.gov ↗ · nvd.nist.gov ↗

What to do

Three steps, in this order

Step 1

Apply the vendor fix and restart the affected service.

Step 2

Put the login or management interface behind a VPN or allow-list; a bypass makes passwords irrelevant.

Step 3

Rotate credentials and session keys the product holds, and review accounts and configuration changes since the listing date.

CISA's required action	Apply mitigations in accordance with vendor instructions, ensuring compliance with CISA’s BOD 26-04 Prioritizing Security Updates Based on Risk (see URL in Notes) guidance and CISA’s “Forensics Triage Requirements” (see URL in Notes). Follow applicable BOD 26-04 guidance for cloud services or discontinue use of the product if mitigations are unavailable. Stakeholders are responsible for evaluating each asset's internet exposure and ensuring adherence to BOD 26-04 patching guidelines.

CISA's required action

Apply mitigations in accordance with vendor instructions, ensuring compliance with CISA’s BOD 26-04 Prioritizing Security Updates Based on Risk (see URL in Notes) guidance and CISA’s “Forensics Triage Requirements” (see URL in Notes). Follow applicable BOD 26-04 guidance for cloud services or discontinue use of the product if mitigations are unavailable. Stakeholders are responsible for evaluating each asset's internet exposure and ensuring adherence to BOD 26-04 patching guidelines.

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Questions

CVE-2026-67277 in short

Is CVE-2026-67277 being exploited?

Yes. CISA added CVE-2026-67277 to its Known Exploited Vulnerabilities catalogue on 10 September 2026, which it does only on evidence of exploitation in the wild.

What is the CISA deadline for CVE-2026-67277?

US federal agencies must remediate it by 13 September 2026. Everyone else should treat that date as the latest safe point to patch an internet-facing system.

How likely is CVE-2026-67277 to be exploited in the next 30 days?

FIRST's Exploit Prediction Scoring System gives it 1.6%, the 75th percentile of every CVE it scores.

How do I fix CVE-2026-67277?

Apply the vendor fix and restart the affected service. Put the login or management interface behind a VPN or allow-list; a bypass makes passwords irrelevant. Rotate credentials and session keys the product holds, and review accounts and configuration changes since the listing date.

Same vendor

Other MikroTik vulnerabilities being exploited

CVE	Product	Type	Listed
CVE-2026-67279	RouterOS	exploited vulnerability	25 September 2026
CVE-2026-86060	RouterOS	privilege escalation	10 September 2026

Sources: CISA Known Exploited Vulnerabilities catalogue (released 10 November 2026) and FIRST EPSS. Page compiled automatically by SAK T.L.M, the threat-intelligence tool of SAK T.E.C, on 13 November 2026.