MikroTik RouterOS SSH key check allows user impersonation
RouterOS does not compare the complete RSA public key when matching SSH auth — checking key type and modulus but omitting the exponent. An attacker who knows an authorized RSA modulus can forge a valid signature and open an SSH command channel as the target user. Fixed in 7.24.2, 7.23.4, and 6.49.21.
Also tracked as CVE-2026-67276 · MikroTrick
First observed
Sep 5, 2026
Last observed
Sep 5, 2026
Last reviewed
Sep 20, 2026
Tracking ended
Sep 5, 2026
Uncertainty and limitations
Read the evidence limits before acting on this record.
Confirm your RouterOS train (6.x vs 7.x) before choosing the fixed build.
- Requires SSH exposure and knowledge of an authorized RSA modulus.
- Fixed builds from pack: 7.24.2, 7.23.4, 6.49.21.
- HOL blog is operator guidance, not a substitute for CERT.pl / MikroTik.
Timeline
Reviewed events, oldest first, each tied to a verified source.
- Disclosure
CVE-2026-67276 MikroTik RouterOS SSH RSA key matching flaw disclosed.
- Update
HOL Guard published operator blog coverage for CVE-2026-67276.
Publication clock: 359.5 hours from reviewed disclosure timestamp to HOL publication; 12-hour critical target; historical backfill outside target.
Guard coverage and non-coverage
What Guard's reviewed coverage assertions do and do not claim for this campaign.
No Guard coverage mapping is published for this record.
Defensive policy guidance
Reviewed starting points for defending against this campaign's artifact classes.
No campaign-specific policy guidance is published.
Reviewed artifacts and indicators
Published values are defanged (for example hxxps and [.] blocks) so nothing here is copy-paste executable.
Reviewed artifacts
The specific artifacts this record concerns, as reviewed. Names and versions are shown as text; a registry link is not recorded here.
RouterOS@>=7.24 <7.24.2 || >=7.0.0 <7.23.4 || >=6.0.0 <6.49.21mikrotikpackage
Sources
Every claim on this record is traceable to the sources below.
Reviewed in full by HOL Guard Security Publishing.
- Published
- Last full review
- Last modified
Record HGTC-2026-7E9381C6.