CVE-2026-67276
SSH user impersonation possible in Mikrotik RouterOS
CRITICAL 9.2Exploited per ENISA since 2026-09-05
At a glance
- Source
- NVD
- EPSS
- EPSS 8.94 % · percentile 95 ()
- State
- PUBLISHED
- Published
- Updated
- Assigner
- CERT-PL
- NVD status
- Analyzed
Description
RouterOS does not compare the complete RSA public key when matching an SSH authentication request to an authorized user key, checking the key type and modulus but omitting the exponent. Because signature verification uses the client-supplied key, an attacker knowing an authorized RSA modulus can supply a key with exponent one, forge a valid signature, and open an SSH command channel as the target user without the private key.This issue affects only 7.x branch was fixed in versions: 7.23.4 (Long-term) and 7.24.2 (Stable)
Weaknesses (CWE)
- CWE-347 — Improper Verification of Cryptographic Signature
References
- https://cert.pl/en/posts/2026/09/mikrotik-routeros-cve
- https://cert.pl/en/posts/2026/09/vulnerabilities-in-mikrotik-routeros-actively-exploited/
- https://npratley.net/reversing-mikrotiks-silent-patch-the-routeros-7-23-4-fix-they-wouldnt-explain/
- https://mikrotik.com/supportsec/september-2026-vulnerability/
- https://forum.mikrotik.com/t/7-23-4-long-term-is-released/272801
- https://forum.mikrotik.com/t/7-24-2-stable-is-released/272800
Scores
| Version | Score | Vector | Scored by |
|---|---|---|---|
| CVSS 4.0 | CRITICAL 9.2 | CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N | CERT-PL |
| CVSS 4.0 | CRITICAL 9.2 | CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X | NVD · cvd@cert.pl (Secondary) |
| CVSS 3.1 | HIGH 8.1 | CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H | NVD · nvd@nist.gov (Primary) |
European references
- ENISA EUVD · EUVD-2026-72024
- GCVE · GCVE-0-2026-67276
Affected configurations (NVD CPE)
cpe:2.3:o:mikrotik:routeros:*:*:*:*:*:*:*:*≥ 7.9 < 7.23.4cpe:2.3:o:mikrotik:routeros:*:*:*:*:*:*:*:*≥ 7.24 < 7.24.2
Affected products
| Product | Versions |
|---|---|
| Mikrotik · RouterOS | affected 7.24 < 7.24.2 ; affected 7.9 < 7.23.4 |
Sources
| Source | Licence |
|---|---|
| CVE List (CVEProject cvelistV5) | CVE Program Terms of Use |
| EPSS (FIRST.org) | FIRST — attribution requested |
| ENISA EUVD | ENISA — reproduction authorised, source acknowledged |
| NVD (NIST) via fkie-cad/nvd-json-data-feeds | Public domain — this product uses data from the NVD API but is not endorsed or certified by the NVD |