Improper Verification of Cryptographic Signature in MikroTik RouterOS - CVE-2026-67278
Published: September 6, 2026
Vulnerability identifier: #VU147168
CSH Severity: Medium
CVSS v4: 6.3 [CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-67278
CWE-ID: CWE-347
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote attacker to impersonate TLS servers.
The vulnerability exists due to improper verification of cryptographic signatures in the RouterOS X.509 validation logic when validating malformed RSA/PKCS#1 v1.5 signatures. A remote attacker can forge a trusted intermediate certificate for arbitrary hostnames to impersonate TLS servers.
Exploitation requires control of or the ability to redirect an outbound RouterOS TLS connection and relies on the trusted e=3 root CA.
Affected software
MikroTik RouterOS
How to mitigate CVE-2026-67278
Install security update from vendor's website.
MikroTik RouterOS - addressed in versions 6.49.21, 7.23.4, 7.24.2