{"id":"CVE-2026-67278","aliases":[],"url":"https://o3.security/vulnerability/CVE-2026-67278","summary":"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…","details":"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.\n\n\n\nThis issue affects only 7.x branch was fixed in versions: 7.23.6 (Long-term) and 7.24.3 (Stable).\nReleases 7.23.4 and 7.24.2 included an incomplete fix.","published":"2026-09-05T20:17:18.257","modified":"2026-09-25T14:56:04.743","cvss":{"score":9.1,"severity":"CRITICAL","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N"},"epss":null,"cisaKev":null,"exploitsKnown":null,"affectedPackages":[],"fix":null,"references":[{"type":"ADVISORY","url":"https://cert.pl/en/posts/2026/09/mikrotik-routeros-cve"},{"type":"ADVISORY","url":"https://cert.pl/en/posts/2026/09/vulnerabilities-in-mikrotik-routeros-actively-exploited/"},{"type":"WEB","url":"https://forum.mikrotik.com/t/7-23-6-long-term-is-released/273139"},{"type":"WEB","url":"https://forum.mikrotik.com/t/7-24-3-stable-is-released/273138"},{"type":"ADVISORY","url":"https://mikrotik.com/supportsec/september-2026-vulnerability/"},{"type":"EXPLOIT","url":"https://npratley.net/reversing-mikrotiks-silent-patch-the-routeros-7-23-4-fix-they-wouldnt-explain/"}],"provenance":{"sources":["OSV.dev","NVD","FIRST.org (EPSS)"],"lastVerified":"2026-09-25T14:56:04.743"}}