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Vulnerabilities / CVE-2026-67279

CVE-2026-67279

Published 2026-09-05 · published (not yet in NVD)

CVE-2026-67279

SSH Pre-Authentication Rekey State Bypass in MikroTik RouterOS

Exploited in the wild: CISA added it to the Known Exploited Vulnerabilities catalog on 2026-09-25, with a fix-by date of 2026-09-28. Patch it first.

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.

6.9 MEDIUM
CVSS 4.0 · CNA
2.3%
chance of exploitation in the next 30 days (EPSS; higher than 83% of CVEs)

RouterOS SSH enters the connection protocol after a client-requested rekey even though user authentication was never attempted, allowing an unauthenticated client to open a session channel and send an exec request. On affected builds the server dispatches the command, enabling unauthenticated creation, overwrite, and reconstruction of files in the RouterOS managed file namespace, including support files containing configuration and diagnostic data.This issue was fixed in versions: 6.49.21 (Long-term), 7.23.4 (Long-term) and 7.24.2 (Stable)

Scores

6.9CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:NCNA

Affected products

  • Mikrotik RouterOS: 7.24 to < 7.24.2; 7.0.0 to < 7.23.4; 6.0.0 to < 6.49.21

Weakness: CWE-841

7 references (advisories, patches, write-ups)

Sources: CVE.org, FIRST EPSS. Missing ones did not answer or have no record yet.

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