Description
MikroTik RouterOS accepts malformed RSA/PKCS#1 v1.5 signatures during X.509 validation. 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.

This issue was fixed in versions: 6.49.21 (Long-term), 7.23.4 (Long-term) and 7.24.2 (Stable)
Published: 2026-09-05
Score: 6.3 Medium
EPSS: n/a
KEV: No
Impact: n/a
Action: n/a
AI Analysis

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Remediation

No vendor fix or workaround currently provided.

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Advisories

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History

Sat, 05 Sep 2026 20:45:00 +0000

Type Values Removed Values Added
Description MikroTik RouterOS accepts malformed RSA/PKCS#1 v1.5 signatures during X.509 validation. 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. This issue was fixed in versions: 6.49.21 (Lont-term), 7.23.4 (Lont-term) and 7.24.2 (Stable) MikroTik RouterOS accepts malformed RSA/PKCS#1 v1.5 signatures during X.509 validation. 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. This issue was fixed in versions: 6.49.21 (Long-term), 7.23.4 (Long-term) and 7.24.2 (Stable)

Sat, 05 Sep 2026 20:15:00 +0000

Type Values Removed Values Added
Description MikroTik RouterOS accepts malformed RSA/PKCS#1 v1.5 signatures during X.509 validation. 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. This issue was fixed in versions: 6.49.21 (Lont-term), 7.23.4 (Lont-term) and 7.24.2 (Stable)
Title TLS server impersonation possible in Mikrotik RouterOS
First Time appeared Mikrotik
Mikrotik routeros
Weaknesses CWE-347
CPEs cpe:2.3:a:mikrotik:routeros:*:*:*:*:*:*:*:*
Vendors & Products Mikrotik
Mikrotik routeros
References
Metrics cvssV4_0

{'score': 6.3, 'vector': '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'}


Subscriptions

Mikrotik Routeros
cve-icon MITRE

Status: PUBLISHED

Assigner: CERT-PL

Published:

Updated: 2026-09-05T20:40:10.587Z

Reserved: 2026-07-29T11:59:30.538Z

Link: CVE-2026-67278

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

Published: 2026-09-05T20:17:18.257

Modified: 2026-09-05T21:16:50.503

Link: CVE-2026-67278

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-09-05T22:30:17Z

Weaknesses