MikroTik router flaws allow takeover without a password
Attackers actively exploit chained MikroTik RouterOS SSH flaws CVE-2026-67276 and CVE-2026-86060, bypassing authentication and escalating to admin to seize edge routers.
CERT Polska warns of active exploitation of a two-flaw chain dubbed 'MikroTrick' against internet-exposed MikroTik RouterOS devices with SSH remote management enabled. CVE-2026-67276 is an SSH authentication bypass in RSA public-key handling, and CVE-2026-86060 is a privilege-escalation flaw triggered via a specially crafted username, letting attackers gain full administrator control without a password. Patched RouterOS packages are already public, and MikroTik added a startup detection that flags unauthorized configuration changes. Compromised edge routers enable DNS hijacking, traffic capture, remote-access tunnels, firewall changes, and lateral attacks.
- MikroTrick chain combines auth bypass (CVE-2026-67276) and priv-esc (CVE-2026-86060)
- Requires vulnerable RouterOS with SSH exposed to the internet
- Patched RouterOS available; update via Check for updates or vendor packages
- RouterOS now flags suspicious config changes at startup for audit
- Defenders should restrict SSH to trusted IPs and audit flagged devices
Vulnerabilities mentionedAll →
| CVE | Vulnerability | CVSS | EPSS | Flags | Affected | Exposure | Published |
|---|---|---|---|---|---|---|---|
| CVE-2026-67276 | SSH RSA Authorized-Key Bypass in MikroTik RouterOS 7.x MikroTik RouterOS 7.x fails to compare the complete RSA public key when matching an SSH authentication attempt against an authorized user key, checking the key type and modulus but omitting the exponent. Because RouterOS verifies the signature against the client-supplied key, an attacker who knows the modulus of an authorized RSA key can present a key with exponent 1 and a forged signature and be accepted as that user without possessing the private key. Successful exploitation opens an SSH command channel as the target user, giving the attacker control of the router without a password or key. Only the RouterOS 7.x branch is affected, with fixes released in 7.23.4 (Long-term) and 7.24.2 (Stable). A public proof-of-concept is available and related reporting describes active campaigns hijacking MikroTik routers using chained RouterOS flaws, though this CVE is not in CISA KEV and its 30-day EPSS probability is low (0.2%). Do: Upgrade affected devices to RouterOS 7.23.4 (Long-term) or 7.24.2 (Stable) or later. Until patched, restrict SSH access to trusted management networks and, if feasible, remove or replace RSA authorized keys with other key types. Check devices for signs of compromise highlighted in recent reporting, such as an unexpected SSH user named '-2'. | 9.2 | <1% |
| mass~1M RouterOS 7.x devices (installed base in the millions; hundreds of thousands internet-exposed, with SSH a standard management service) | ||
| CVE-2026-86060 | Argument-Injection Flaw in MikroTik RouterOS SSH Login Enables Privilege Escalation CVE-2026-86060 is an argument-injection flaw (CWE-88) in MikroTik RouterOS's SSH login path: when a login supplies a username beginning with a prohibited character, the RouterOS login helper mishandles the argument, allowing the trusted RouterOS policy mask to be changed and privileges to be escalated. An unauthenticated attacker only needs the ability to reach the router's SSH service, since exploitation happens during the SSH login process itself. By altering the policy mask the attacker gains elevated rights on the device, and news reports indicate attackers have used this technique — including logins with usernames such as '-2' — as part of chains that take over routers without needing a password. Any RouterOS deployment running versions before the fixes (6.49.21 Long-term, 7.23.4 Long-term, 7.24.2 Stable) with SSH enabled or reachable is affected, with internet-exposed SSH at highest risk. Multiple outlets report the RouterOS flaws are being actively exploited in the wild, although no public proof-of-concept is known and the flaw is not yet in CISA KEV. Do: Upgrade RouterOS to 6.49.21 (Long-term), 7.23.4 (Long-term) or 7.24.2 (Stable) as applicable. Until patched, restrict SSH (TCP 22) to trusted management networks or disable the SSH service if unused, and review authentication logs and user/group policy settings for tampering — reports indicate attackers log in with usernames beginning with '-' (e.g., '-2'). | 9.2 | 1% | KEV PoC ×2 |
| mass≈1M+ devices: hundreds of thousands to over a million RouterOS devices are routinely observed internet-exposed, and far more expose SSH to the LAN |
Full article475 words · extracted from malwarebytes.com · click to collapse
CERT Polska warns that attackers are actively exploiting a chain of critical MikroTik RouterOS flaws to seize control of routers exposed to the internet.
Although the warning comes from Poland’s national cybersecurity response team, MikroTik routers are sold worldwide, including in the US. The vulnerabilities can affect users anywhere if their router is running a vulnerable version of RouterOS and its SSH remote-management service is accessible from the internet.
Attackers are exploiting two vulnerabilities, collectively dubbed “MikroTrick,” to take full control of vulnerable devices, CERT Polska says.
A compromised router is especially serious because it sits at the edge of your network. An intruder may be able to change DNS settings, redirect or capture traffic, create remote-access tunnels, alter firewall rules, or use the device as a foothold to attack other devices on the network.
Two of the six disclosed vulnerabilities form the chain of compromise known as MikroTrick. The first, tracked as CVE-2026-67276, is an SSH authentication-bypass flaw in the handling of RSA public keys. The second, CVE-2026-86060, is a privilege-escalation flaw involving a specially crafted username in the SSH login process.
Put simply, the first flaw lets attackers get in without a password, and the second lets them make themselves an administrator.
SSH (short for Secure Shell) is a network protocol that establishes encrypted connections between computers for secure remote access.
CERT Polska issued the warning because the patched RouterOS packages are already public, and their comparative analysis has allowed the community to reconstruct some of the flaws they fix.
How to stay safe
MikroTik router owners should install the latest RouterOS security update as soon as possible. Use the router’s update mechanism or obtain the supported package directly from MikroTik. The update option should be available under Check for updates.
You should also remove public access to the router’s management services. Make sure that SSH is not accessible from untrusted networks. If remote administration is necessary, limit access to known IP addresses.
Remote management should be the exception, not the default. MikroTrick demonstrates that a strong password alone cannot protect a device from an authentication-bypass vulnerability.
MikroTik has added a detection mechanism that scans the configuration at startup for selected signs of unauthorized changes. If it finds any, RouterOS disables the recognized suspicious entries and sets the device’s Flagged status to Yes. Administrators can check this with /system/device-mode/print.
RouterOS restricts several potentially abusable functions while the device is flagged, but MikroTik stresses that the router’s full configuration still needs to be audited before the flag is cleared.
From reporting threats to removing them.
Cybersecurity risks should never spread beyond a headline. Keep threats off your devices by downloading Malwarebytes today.
About the author
Was a Microsoft MVP in consumer security for 12 years running. Can speak four languages. Smells of rich mahogany and leather-bound books.
Text extracted automatically; images, tables and formatting may be missing. Original: https://www.malwarebytes.com/blog/news/2026/09/mikrotik-routers-can-be-taken-over-without-password