Reference page — cumulative record through Saturday, October 3, 2026 UTC. Reference pages update as the archive grows; only dated daily editions are immutable pages of record.

CVE-2026-67278

CVE-2026-67278MEDIUM

Mikrotik RouterOS — TLS server impersonation possible in Mikrotik RouterOS

  AV  AC  AT  PR  UI  VC  VI  VA   CVSS    EPSS   %ile   KEV
   N   L   P   N   N   L   L   N    6.3   .0025   15.1     —

AFFECTED
  Product   Versions  Fixed
  RouterOS  7.24 –    —

TIMELINE
  Jul 29  Reserved by CERT-PL
  Sep 5   Published (CNA: CERT-PL)
  Sep 7   EXPLOIT PUBLISHED — CVE-2026-67278 (Mikrotik RouterOS). Public exploit reference added.
  Sep 8   EXPLOIT PUBLISHED — CVE-2026-67278 (Mikrotik RouterOS). Public exploit reference added.
  Sep 17  EXPLOIT PUBLISHED — CVE-2026-67278 (Mikrotik RouterOS). Public exploit reference added.
  Sep 25  EXPLOIT PUBLISHED — CVE-2026-67278 (Mikrotik RouterOS). Public exploit reference added.

CWE-347 · CNA: CERT-PL · CVSS v4.0 · 9 references · NVD status: Analyzed

Description

MikroTik RouterOS accepts malformed RSA/PKCS#1 v1.5 signatures across RSA-based services, including TLS/X.509 certificate validation and SSH host-key authentication. Because its trust store includes an e=3 root CA, an attacker controlling or redirecting an outbound RouterOS TLS connection can use the root’s public certificate - without its private key - to forge a trusted intermediate and issue certificates for arbitrary hostnames, enabling TLS server impersonation. The same permissive verification also undermines RSA-based SSH authentication. This issue affects only 7.x branch was fixed in versions: 7.23.6 (Long-term) and 7.24.3 (Stable). Releases 7.23.4 and 7.24.2 included an incomplete fix.

Lifecycle

Complete event history — 6 events, chronological
Date	Event	Detail
July 29, 2026	Reserved	Reserved by CERT-PL
September 5, 2026	Published	Published (CNA: CERT-PL)
September 7, 2026	EXPLOIT PUBLISHED	EXPLOIT PUBLISHED — CVE-2026-67278 (Mikrotik RouterOS). Public exploit reference added.
September 8, 2026	EXPLOIT PUBLISHED	EXPLOIT PUBLISHED — CVE-2026-67278 (Mikrotik RouterOS). Public exploit reference added.
September 17, 2026	EXPLOIT PUBLISHED	EXPLOIT PUBLISHED — CVE-2026-67278 (Mikrotik RouterOS). Public exploit reference added.
September 25, 2026	EXPLOIT PUBLISHED	EXPLOIT PUBLISHED — CVE-2026-67278 (Mikrotik RouterOS). Public exploit reference added.

Affected

Affected products and packages — 1 row
Vendor	Product / Package	Ecosystem	Version introduced	Fixed
Mikrotik	RouterOS	—	7.24	—

Weaknesses

CWE-347

References (9)

https://cert.pl/en/posts/2026/09/mikrotik-routeros-cve [Third Party Advisory]
https://cert.pl/en/posts/2026/09/vulnerabilities-in-mikrotik-routeros-actively-exploited/ [Mitigation, Third Party Advisory]
https://forum.mikrotik.com/t/6-49-21-long-term-is-released/272802
https://forum.mikrotik.com/t/7-23-4-long-term-is-released/272801
https://forum.mikrotik.com/t/7-23-6-long-term-is-released/273139 [Release Notes]
https://forum.mikrotik.com/t/7-24-2-stable-is-released/272800
https://forum.mikrotik.com/t/7-24-3-stable-is-released/273138 [Release Notes]
https://mikrotik.com/supportsec/september-2026-vulnerability/ [Vendor Advisory]
https://npratley.net/reversing-mikrotiks-silent-patch-the-routeros-7-23-4-fix-they-wouldnt-explain/ [Exploit, Third Party Advisory]

Authoritative record: CVE-2026-67278 at cve.org

Vendors: mikrotik

Weaknesses: CWE-347

About this page

This is a reference page, not a dated page of record. It assembles the complete lifecycle of CVE-2026-67278 from the CVE Program record, NVD enrichment, the CISA KEV catalog, EPSS, and OSV advisories. The box score's numbers (CVSS, EPSS, KEV status) are current as of Saturday, October 3, 2026 UTC and are re-derived as the archive grows; only dated daily editions are immutable pages of record. The authoritative source for this identifier is cve.org.