SSH account impersonation via omitted RSA exponent
Published Sep 5, 2026 · Updated Sep 9, 2026
Authentication bypass in MikroTik RouterOS 7.9 through 7.23.3 and 7.24 through 7.24.1 allows remote attackers to impersonate an SSH user. The SSH key-matching path compares the key type and modulus with an authorized RSA key but omits the exponent before verifying the client-supplied signature. Exploitation requires the target username and authorized RSA modulus; the resulting command channel carries the targeted account's privileges.
Summary
What happened
Authentication bypass in MikroTik RouterOS 7.9 through 7.23.3 and 7.24 through 7.24.1 allows remote attackers to impersonate an SSH user. The SSH key-matching path compares the key type and modulus with an authorized RSA key but omits the exponent before verifying the client-supplied signature. Exploitation requires the target username and authorized RSA modulus; the resulting command channel carries the targeted account's privileges.
The record
- CVE
- CVE-2026-67276
- Published
- Sep 5, 2026
- Updated
- Sep 9, 2026
- Vendor
- MikroTik
- Product
- RouterOS
- Classifications
- CWE-347, T1190
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Sep 2, 2026Exploitation reportedActive exploitation of the MikroTrick SSH chain
- Sep 5, 2026CVE publishedPublication date reported by the CVE source.
- Sep 9, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=7.24 <7.24.2
- Affected versionversion=7.9 <7.23.4
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
- forge_e3_ssh.py lab proof of conceptproof of concept · demonstrated
Labels summarize the accepted research assessment. They do not indicate a test against your environment.
Reported exploitation
- Active exploitation of the MikroTrick SSH chainexploit chain
Technologies
Your stack
See the directory against your own environment.
Your stack
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