CVE-2026-67276criticalobserved exploitationCWE-347

CVE-2026-67276: critical vulnerability in Mikrotik RouterOS

SSH user impersonation possible in Mikrotik RouterOS

Published · Updated

Follow this CVE+ Monitor RouterOS

E-mail alert when it lands in KEV, gets a public PoC or its score goes up.

75Vexday Risk Score

Prioritize patching. It exploitation observed by VulnCheck, has an official Brazilian government alert and has a public proof of concept.

ssvc Actcvss 9.2epss 8.9%
from disclosure to weapon1 day
Published on NVDSep 5
1st PoC+1d
VulnCheckSep 5
Official alert in Brazil

Brazil's federal government published an alert, recommendation or bulletin that cites this vulnerability.

Source: CTIR Gov (GSI) and CISC Gov.br, under the CC BY-ND 3.0 license.
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)
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
Affected products
Mikrotik · RouterOS
⚠ Public resources, to assess the exposure of systems you control or are authorized to test. Test only with authorization.
Related CVEs — Mikrotik RouterOS

In the same product, most dangerous first.

CVE-2026-86060CRITICALSSH session privilege manipulation via a crafted username in Mikrotik RouterOSEPSS 6.4%KEVCVE-2026-67279MEDIUMSSH Pre-Authentication Rekey State Bypass in MikroTik RouterOSEPSS 2.3%KEVCVE-2026-67277HIGHKernel memory disclosure and denial of service in MikroTik RouterOS btest serviceEPSS 1.6%KEVCVE-2026-67281HIGHUnauthenticated file read in Mikrotik RouterOSEPSS 0.7%CVE-2023-32154HIGHMikrotik RouterOS RADVD Out-Of-Bounds Write Remote Code Execution VulnerabilityEPSS 0.6%CVE-2025-6443HIGHMikrotik RouterOS VXLAN Source IP Improper Access Control VulnerabilityEPSS 0.6%