MikroTik RouterOS
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…
Severity = CVSS. Probability = EPSS (FIRST). Exploitation = public signals: KEV, EUVD, ransomware, EPSS above 10 %, no account required.
Exploitation probability EPSS · FIRST
Exploitation signals 2 / 5
- KEV catalog (CISA)no
- Exploited in EUVD (ENISA)05 Sept 2026
- Used by ransomwareno
- EPSS above 10 %8.9%
- No account, over the networkyes
What to do
Fix
Apply the vendor’s fix as soon as it is available.
Meanwhile
Take the service off the internet or restrict access to it, watch the logs and look for signs of compromise.
Manufacturers (CRA)
Exploited vulnerability in your product: early warning to ENISA within 24 h, then notification within 72 h (Article 14 of the Cyber Resilience Act). The CRA explained
Description ENISA EUVD
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)
Affected products
- 7.24 <7.24.2
- 7.9 <7.23.4
Open source packages OSV
Affected libraries according to OSV, with fixed versions.
Timeline
-
Published
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Exploitation reported (ENISA)
References
Other exploited vulnerabilities from the same vendor
- CVE-2026-67279Mikrotik RouterOS Improper Enforcement of Behavioral Workflow Vulnerability4.6 · Actively exploited
- CVE-2026-86060MikroTik RouterOS Improper Neutralization of Argument Delimiters in a Command Vulnerability5.7 · Actively exploited
- CVE-2026-67277MikroTik RouterOS Missing Authentication for Critical Function Vulnerability5.4 · Actively exploited
- CVE-2018-7445MikroTik RouterOS Stack-Based Buffer Overflow Vulnerability8.3 · Background exploitation
- CVE-2018-14847MikroTik Router OS Directory Traversal Vulnerability8.9 · Background exploitation