Hackers exploit new MikroTik RouterOS flaws to hijack routers
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.
MikroTik patches flaws currently being exploited to take over routers
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.
Unpatched Zimbra servers are falling to CVE-2026-73570 attacks
Attackers are exploiting unpatched Zimbra servers via CVE-2026-73570; 274 instances compromised, and CISA added the flaw to its KEV catalog.
The Shadowserver Foundation counted at least 274 compromised internet-facing Zimbra Collaboration Suite instances exploited through CVE-2026-73570, up from 155 on August 20. The unauthenticated code injection flaw affects servers with the optional zimbra-snmp package and SNMP notifications enabled, allowing arbitrary OS command execution via crafted SMTP requests. Synacor patched the issue in ZCS v10.1.20 on July 20, 2026, and at least 8,200 instances remain unpatched. CISA added the flaw to its Known Exploited Vulnerabilities catalog and gave US federal civilian agencies three days to remediate and check for compromise.
Russian-Linked Hackers Accessed Polish Power Plant OT Network Through Private APN, Says CERT.PL
CERT.PL disclosed that Russian-linked hackers accessed a Polish combined heat and power plant's OT network through a private APN in 2025.
Poland's CERT (CERT.PL) released details of a 2025 attack on a Polish combined heat and power plant. Russian-linked hackers accessed the plant's OT network through a private APN. The disclosure adds to a series of intrusions against Polish critical infrastructure attributed to Russian-linked actors.
Attackers Exploit Zimbra SNMP Flaw for Unauthenticated Remote Code Execution
CERT Polska and CISA report active exploitation of Zimbra RCE CVE-2026-73570, with 267 instances compromised per Shadowserver.
CVE-2026-73570 (CVSS 8.9) enables unauthenticated command injection and remote code execution in Zimbra Collaboration before 10.1.20 when the optional zimbra-snmp package is installed and SNMP notifications are enabled, via crafted SMTP requests. CISA added the flaw to its KEV catalog on August 21, 2026, with a federal patch deadline of August 24. The Shadowserver Foundation counted 267 compromised instances as of August 24, 2026, led by the US (46), Sweden (21), France (20) and Germany (17). Separately, Russia-linked Laundry Bear has weaponized Zimbra stored XSS CVE-2025-66376 against Western government and commercial mail servers since at least July 2025, delivering the ZimReaper payload.
Attackers Hijack MikroTik Routers Through Internet-Exposed SSH Without Authentication
CERT Polska warns attackers exploit internet-exposed MikroTik SSH for unauthenticated full admin control; attacks observed since at least September 2.
CERT Polska warned on September 5 that attackers exploit MikroTik routers with internet-reachable SSH to gain full administrative control without authentication, calling the two-flaw combination 'MikroTrick'. Successful attacks date to at least September 2; no victim count or attacker identity was disclosed. MikroTik shipped fixed RouterOS releases: 6.49.21, 7.23.4 (with 7.23.5 fixing an IPv6 DHCP regression), 7.24.2, and 7.25beta3. CERT recommends immediate updates, checking for unauthorized configuration changes, and restricting SSH, WWW/WWW-SSL, and bandwidth-test services on unpatched devices.
Your MikroTik Router May Already Be Compromised: Look for SSH User “-2”
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.
Week in review: Salesforce and ServiceNow portals exposed for 17 months, exploited Metabase 0-day
Weekly digest: exploited Metabase zero-day breached Framework; Salesforce/ServiceNow portals read for 17 months; Microsoft patched 400+ flaws.
Help Net Security's week in review aggregates top stories: a 'City-Forum' campaign tracked by Reco has been pulling records from Salesforce and ServiceNow portals worldwide for 17 months, and Framework suffered a breach via an exploited Metabase zero-day exposing customer contact and IP data. It also covers Microsoft's August 2026 Patch Tuesday fixing 400+ flaws including exploited zero-day CVE-2026-68820, Cisco's fix for exploited firewall DoS bug CVE-2026-20349 (added to CISA KEV), and a second N-able N-central hotfix for actively exploited CVE-2026-18577. Other items include GitHub expanding Dependabot malware alerts to eight package ecosystems and EU AI Act enforcement beginning on 2 August 2026.