Argument-Injection Flaw in MikroTik RouterOS SSH Login Enables Privilege Escalation
CISA: MikroTik RouterOS Improper Neutralization of Argument Delimiters in a Command Vulnerability
CVSS 4.0
9.2critical
EPSS
1%p63
Published
()
KEV added
AI analysis
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.
What to 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').
Affected
MikroTik RouterOS v6 (Long-term channel)
versions prior to 6.49.21 (fixed in 6.49.21)
MikroTik RouterOS v7 (Long-term channel)
versions prior to 7.23.4 (fixed in 7.23.4)
MikroTik RouterOS v7 (Stable channel)
versions prior to 7.24.2 (fixed in 7.24.2)
Estimated exposure
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 — MikroTik RouterOS is one of the most widely deployed router platforms across SOHO, ISP/WISP and hosting environments, and long-running public internet scans (e.g., Shodan/Censys) consistently surface hundreds of thousands to over a million…
Order-of-magnitude estimate by the model from install counts, market share and public scan data it knows; verify before quoting.
Description
RouterOS contains an argument-handling flaw in the SSH login path involving usernames that begin with a prohibited character, allowing for the trusted RouterOS policy mask to be changed, leading to privilege escalation. Exploitation requires an unauthenticated SSH session to reach the RouterOS login helper.This issue was fixed in versions: 6.49.21 (Long-term), 7.23.4 (Long-term) and 7.24.2 (Stable)
CISA Known Exploited Vulnerability
Affected
MikroTik RouterOS
Required action
Apply mitigations in accordance with vendor instructions, ensuring compliance with CISA’s BOD 26-04 Prioritizing Security Updates Based on Risk (see URL in Notes) guidance and CISA’s “Forensics Triage Requirements” (see URL in Notes). Follow applicable BOD 26-04 guidance for cloud services or discontinue use of the product if mitigations are unavailable. Stakeholders are responsible for evaluating each asset's internet exposure and ensuring adherence to BOD 26-04 patching guidelines.
MikroTik RouterOS SSH auth-bypass chain MikroTrick (CVE-2026-67276 plus CVE-2026-86060) is actively exploited; patch to 7.24.2/7.23.5/6.49.21.
Attackers are actively exploiting a chain dubbed MikroTrick that combines CVE-2026-67276 (CVSS 9.2), an SSH authentication bypass in RouterOS RSA public key verification, and CVE-2026-86060, an SSH session privilege escalation, giving full admin control of internet-exposed MikroTik devices without the private key. Exploitation began around September 2, 2026, a day before MikroTik's September 3 patches, with confirmed compromises including creation of an 'ops' account; attacks traced to IPs 82.192.72.4 (Leaseweb) and 103.102.31.18. Fixed versions include 7.25beta3, 7.24.2, 7.23.4, 7.23.5 and 6.49.21. Defenders should check logs for failed logins with username '-2' and inspect /system history for ssh:-2@<IP> entries attached to configuration changes.
MikroTik patches six RouterOS flaws; two chained as MikroTrick are actively exploited via SSH to fully compromise exposed routers.
MikroTik released patches for six RouterOS vulnerabilities, including actively exploited MikroTrick chain: CVE-2026-67276 (9.2, SSH auth bypass) and CVE-2026-86060 (9.2, privilege manipulation), plus CVE-2026-67277 (8.8). CERT Poland confirms exploitation since September 2, creating an 'ops' account from IPs 82.192.72.4 and 103.102.31.18. Fixed in RouterOS 7.25beta3, 7.24.2, 7.23.4, and 6.49.21; Shadowserver found 120,000+ SSH-exposed MikroTik devices.
MikroTik patches six RouterOS flaws, including the actively exploited MikroTrick SSH chain (CVE-2026-67276, CVE-2026-86060) enabling unauthenticated full router takeover.
MikroTik released patches in RouterOS 7.25 beta 3, 7.24.2, 7.23.4, and 6.49.21 for six vulnerabilities found by CERT Polska, affecting the SSH server/client, bandwidth-test service, X.509 handling, and WebFig. CVE-2026-67276, an RSA public-key validation flaw in the SSH server, lets an attacker who knows a username and key modulus authenticate as that user; CVE-2026-86060 then escalates privileges to root via special-character username handling. CERT Polska confirmed attackers are exploiting the chain to take full control of RouterOS devices with SSH exposed to the internet. Shadowserver Foundation scans show over 122,500 devices with internet-reachable SSH, concentrated in Brazil, the US, and Indonesia.
Attackers actively exploit a MikroTik RouterOS SSH authentication bypass and privilege escalation chain, dubbed MikroTrick, to fully hijack internet-exposed routers.
Poland's CERT, with help from GPT-5.5-cyber and GPT-5.6-sol, discovered and confirmed active exploitation of a MikroTik RouterOS chain dubbed MikroTrick: SSH authentication bypass CVE-2026-67276 (incomplete RSA public key validation) chained with privilege escalation CVE-2026-86060 (crafted usernames granting full administrative privileges). A third flaw, CVE-2026-67277, allows unauthenticated kernel memory leaks or router crashes via the bandwidth-test service. Fixes shipped September 3 in RouterOS 7.25beta3, 7.24.2, 7.23.4, and 6.49.21, adding a startup compromise-detection mechanism. Shadowserver data showed 122,500 MikroTik devices with exposed SSH interfaces as of September 5, and the CERT published IoCs including two attacker IP addresses.
CERT Polska confirms attackers exploit chained MikroTik RouterOS SSH flaws to hijack devices without authentication; patches released in four RouterOS versions.
CERT Polska discovered six RouterOS vulnerabilities and confirmed active attacks chaining CVE-2026-67276 (CVSS 9.2, SSH authentication bypass caused by comparing only RSA key moduli) and CVE-2026-86060 (CVSS 9.2, privilege escalation via crafted usernames), dubbed MikroTrick. A third flaw, CVE-2026-67277 (CVSS 8.8) in the bandwidth-test service, can expose kernel memory or crash devices. Shadowserver counted about 122,500 MikroTik devices with SSH exposed; attackers created a privileged 'ops' account from IP 82.192.72.4, active since September 2. Fixes shipped in RouterOS 7.25beta3, 7.24.2, 7.23.4, and 6.49.21, adding startup configuration scanning with a 'Flagged' marker for unauthorized changes.
Check Point weekly digest: Microsoft's record 974-vuln Patch Tuesday ships two actively exploited Windows zero-days; IDScan.net, Mathspace, Revolut suffer breaches.
Microsoft's September 2026 Patch Tuesday addressed a record 974 vulnerabilities, including two actively exploited privilege-escalation zero-days, CVE-2026-85880 and CVE-2026-81963, plus 20 flaws allowing unauthenticated remote code execution. Disclosed breaches include IDScan.net (identity documents), Mathspace (over 1 million people via Metabase CVE-2026-72898), Revolut, and Florida DMV (ShinyHunters). GitLab fixed critical CVSS 10.0 path traversal CVE-2026-85706, and MikroTik fixed chainable RouterOS flaws CVE-2026-67276 and CVE-2026-86060. The report also covers the PuzzleMask LLM jailbreak technique, GoldFactory's Gigabud Android fraud, and the BlueMoon Chromium exploit chain (CVE-2026-85046).
CISA added five actively exploited JFrog Artifactory, ConnectWise ScreenConnect, and MikroTik RouterOS flaws to its KEV catalog.
CISA added five actively exploited vulnerabilities to the KEV catalog: CVE-2026-42016 and CVE-2026-42018 in JFrog Artifactory, CVE-2026-84869 in ConnectWise ScreenConnect (CVSS 9.9), and CVE-2026-67277 and CVE-2026-86060 in MikroTik RouterOS. The Artifactory bugs are chained with CVE-2026-82329 to gain administrative control, deploy malicious Groovy plugins, and install Rust-based backdoors. CERT Polska dubbed the RouterOS chain 'MikroTrick'; FCEB agencies must patch between September 13 and 25, 2026.
CISA added two actively exploited MikroTik RouterOS flaws, CVE-2026-67277 and CVE-2026-86060, to its KEV catalog with a September 13 mitigation deadline.
CISA added CVE-2026-67277 and CVE-2026-86060 in MikroTik RouterOS to the Known Exploited Vulnerabilities catalog on September 10, giving federal agencies until September 13 to apply vendor mitigations. CVE-2026-67277 is a missing-authentication flaw (CWE-306) in the bandwidth-test (btest) service that can expose kernel memory and cause denial of service; CVE-2026-86060 (CWE-88) lets attackers manipulate the trusted RouterOS policy mask for privilege escalation. CISA designated CVE-2026-86060 as requiring forensic triage under Binding Operational Directive 26-04, meaning organizations should hunt for compromise indicators, not just patch. Compromised routers could have altered routing rules, persistence, traffic interception, or use as pivots into internal networks.
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.
Canada's Cyber Centre warns of three exploited MikroTik RouterOS vulnerabilities affecting SSH-exposed devices; CISA added two to its KEV catalog.
The Canadian Centre for Cyber Security issued alert AL26-020 for three MikroTik RouterOS vulnerabilities, especially on devices exposing SSH to the internet: CVE-2026-67277 (missing authentication, CWE-306, enabling sensitive information disclosure), CVE-2026-86060 (argument injection, CWE-88, enabling privilege escalation), and CVE-2026-67276 (improper cryptographic signature verification, CWE-347, allowing SSH command channel access without the private key). On September 10, 2026, CISA added CVE-2026-67277 and CVE-2026-86060 to its Known Exploited Vulnerabilities catalog. Fixed versions include RouterOS 6.49.21, 7.23.4 (Long-Term), 7.24.2 (Stable), and 7.25 beta 3.
CISA added two actively exploited MikroTik RouterOS vulnerabilities, CVE-2026-67277 and CVE-2026-86060, to its KEV catalog, mandating federal remediation.
CISA added CVE-2026-67277 (missing authentication for a critical function) and CVE-2026-86060 (improper neutralization of argument delimiters in a command), both in MikroTik RouterOS, to the Known Exploited Vulnerabilities Catalog based on evidence of active exploitation. Under BOD 26-04, Federal Civilian Executive Branch agencies must prioritize rapid remediation of these flaws on publicly exposed assets that grant total control post-exploitation. Agencies are also required to check whether systems were compromised before patches were applied.
Google patched an actively exploited Chrome V8 type confusion zero-day, CVE-2026-85046 (CVSS 8.8), the sixth exploited Chrome zero-day of 2026. CERT Polska warned of the MikroTrick exploit chain (CVE-2026-67276 and CVE-2026-86060, CVSS 9.2) giving unauthenticated full control of MikroTik RouterOS devices via SSH, observed since September 2. Sansec disclosed the StyleSmuggler Magento/Adobe Commerce zero-day used since September 4 to inject a Rust backdoor into online stores, while N-able patched three critical N-central flaws (CVE-2026-86206, CVE-2026-86207, and CVE-2026-86218, CVSS 10.0) with Huntress observing likely exploitation. Elastic and Morphisec also detailed RevStealer, an information stealer spread via game cheats and a fake Claude Desktop app.
Canada's Cyber Centre urges MikroTik RouterOS updates as CVE-2026-67276, CVE-2026-67277 and CVE-2026-86060 are reported exploited in the wild.
Canadian Centre for Cyber Security advisory AV26-887 covers MikroTik RouterOS vulnerabilities affecting versions prior to 6.49.21, 7.23.4, 7.24.2 and 7.25 beta 3. Open-source reporting indicates CVE-2026-67276, CVE-2026-67277 and CVE-2026-86060 are being exploited in the wild. The Cyber Centre urges users and administrators to review the vendor advisories and apply the necessary updates.