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.
Cops, CrowdStrike disrupt Sality botnet by poisoning the network and diverting into sinkholes
Law enforcement and CrowdStrike disrupted the 23-year-old Sality P2P botnet, isolating 15,000+ infected machines and seizing linked domains.
International law enforcement, working with CrowdStrike and the Shadowserver Foundation, executed a peer-to-peer sinkhole operation against Sality, a botnet active since 2003 that delivered malware to more than 15,000 machines worldwide. Sality's primary payload for eight years was EggJagger, a clipboard hijacker that swaps copied bitcoin and ethereum wallet addresses with attacker-controlled ones, yielding at least $150,000 in stolen cryptocurrency. The US Justice Department, FBI, and DoD Office of Inspector General's Defense Criminal Investigative Service seized Sality-linked domains, with parallel action in Bulgaria, Hungary, and Romania. The Shadowserver Foundation is coordinating with ISPs and CSIRTs to identify infections and notify victims.
Global sinkhole operation ends Sality botnet’s 23-year run
Law enforcement, CrowdStrike, and Shadowserver sinkholed the 23-year-old Sality P2P botnet, cutting 15,000+ infected machines from its operator.
Sality, active since 2003 as a file-infecting virus with two P2P networks (versions 3 and 4), distributed credential thieves, spam, proxies, and DDoS payloads, and most recently delivered the EggJagger clipboard hijacker that swapped cryptocurrency wallet addresses for at least $150,000 in operator profit. A coordinated sinkhole operation replaced the botnet's super-peer list with defender-controlled sinkholes, and investigators in the US, Bulgaria, Hungary, and Romania seized payload domains. The Shadowserver Foundation is coordinating ISP and CERT notifications to infected device owners.
Dogged Russia-based botnet dismantled after 23-year run
Law enforcement, CrowdStrike and Shadowserver dismantled the 23-year-old Sality P2P botnet that infected more than 11 million devices.
Sality, a Russia-based peer-to-peer botnet active for 23 years and infecting over 11 million devices, was dismantled by law enforcement working with CrowdStrike and the Shadowserver Foundation. CrowdStrike poisoned the botnet's peer list so infected machines permanently disappeared from the operator's view, while domains were seized in a coordinated effort involving the FBI, Justice Department, Europol and authorities from Bulgaria, Hungary and Romania. The financially motivated operation enabled cryptocurrency theft, DDoS attacks and other cyberattacks, and Europol said the effort dates back to 2017; the operators were not named.
Risky Bulletin: Russia tells data centers to deploy drone defenses
Russia ordered data center operators to deploy drone strike defenses under a Putin decree allowing temporary state takeover of unprotected critical infrastructure.
The Russian government instructed data center operators to deploy protections against drone strikes under a presidential decree signed by Putin that allows temporary state administration of critical infrastructure operators failing to defend against Ukrainian hacks and drone strikes. Although data centers are not formally critical infrastructure in Russia, the decree applies to them because other sectors depend heavily on cloud services; Russia has more than 180 data centers, over 80% in the European region within range of Ukrainian strikes. The digest also reports a Dropbox breach affecting nearly 5,000 accounts via the Lenovo ID integration, spyware attacks on at least 14 Serbians using NoviSpy or Pegasus, and a password recovery attack targeting hundreds of thousands of X accounts tied to the new X Money service. Other items include a 14-hour compromise of Coder's Cloudflare infrastructure delivering malicious Terraform modules, donor data breaches at Davayte and You Are Not Alone via the Stripe/WooCommerce integration, a $2.5M Aquifer crypto heist, and a TVING breach exposing data of almost 40 million accounts.
Attackers Exploit Issabel Framework Flaw Enabling Unauthenticated OS Command Execution
Attackers actively exploit CVE-2026-89026, a hard-coded JWT key flaw enabling unauthenticated OS command execution on Issabel PBX systems.
VulnCheck reported active exploitation of CVE-2026-89026 (CVSS v3.1 9.8) in Issabel Framework, the web framework for the open-source Issabel unified communications PBX. A hard-coded HS256 JWT signing key identical across every installation lets unauthenticated attackers forge bearer tokens and abuse the /pbxapi/manager/originate endpoint, causing Asterisk to execute arbitrary OS commands as the Asterisk user. A patch replacing the hard-coded key with one stored in /etc/issabel.conf shipped August 1, 2026, and the Shadowserver Foundation first observed exploitation on September 9, 2026. Details on real-world abuse, attribution, and scale remain unknown.
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.
PoisonedRefresh: A Fileless Linux Rootkit That Injects PHP Web Shells Into F5 BIG-IP APM Server Memory
Sophos details PoisonedRefresh, a fileless Linux rootkit that injects a memory-resident PHP web shell into F5 BIG-IP APM after exploitation of CVE-2025-53521.
On September 8, 2026, SophosLabs published an analysis of Linux/Agnt-IC (dubbed PoisonedRefresh by ESET) found in compromised F5 BIG-IP Access Policy Manager environments. Initial access leverages CVE-2025-53521, an unauthenticated RCE in BIG-IP APM when an access policy is configured on a virtual server; F5 confirmed exploitation and links the activity to cluster c05d5254, while Shadowserver observed 795 exposed vulnerable endpoints. A first stage hidden in a modified umount binary modifies /usr/sbin/httpd and SELinux configuration and embeds itself in BIG-IP upgrade images for persistence. The second-stage ELF intercepts __libc_start_main, hooks apr_dso_load, and injects a PHP web shell into libphp memory via mmap manipulation, leaving no disk artifacts, and exposes a /bin/bash shell via a local UNIX domain socket instead of a TCP port.
Hackers breach F5 BIG-IP APM devices to deploy Linux rootkit
Sophos analyzed a Linux rootkit on F5 BIG-IP APM devices that injects a fileless PHP web shell, likely after CVE-2025-53521 exploitation.
Sophos analyzed a Linux rootkit targeting F5 BIG-IP APM environments, also tracked by ESET as PoisonedRefresh, which hijacks Apache's apr_dso_load module loader to inject a fileless PHP web shell into memory. The implant intercepts __libc_start_main, hides strings with RC4, creates a password-protected local UNIX socket backdoor for interactive Bash access, and persists across BIG-IP upgrade images while modifying SELinux configuration. It is likely a second-stage payload following exploitation of CVE-2025-53521, a critical RCE flaw F5 reclassified from a DoS issue in March. The ShadowServer Foundation tracked 795 F5 BIG-IP APM endpoints exposed online.
Florida water agency latest to confirm cyber incident as feds warn of nation
A ransomware gang hit Florida's St. Johns River Water Management District as CISA warned of IRGC-linked CyberAv3ngers attacks on exposed Unitronics water-sector PLCs.
The St. Johns River Water Management District, which oversees Florida drinking-water supply planning, confirmed suspicious activity in its IT environment and said containment measures were implemented; a ransomware gang claimed the attack and shared samples of stolen data. Separately, CISA, FBI, NSA, EPA and Israel's INCD warned that IRGC-affiliated CyberAv3ngers are actively compromising Israeli-made Unitronics Vision Series PLCs in the water sector using default credentials since at least November 22. The group, motivated by opposition to Israel-linked products, defaces controller interfaces and could cause deeper cyber-physical effects. Shadowserver found at least 539 Unitronics PLC instances still exposed online, and CNN reported fewer than 10 US water facilities faced recent attacks.
Nearly 22,000 Microsoft Exchange servers remain exposed to critical security flaw (CVE-2026-62911)
About 22,000 Microsoft Exchange servers remain unpatched against critical auth bypass CVE-2026-62911 as a working exploit circulates online.
CVE-2026-62911 is a critical authentication bypass by capture-replay in Microsoft Exchange Server that allows an authorized attacker to elevate privileges over the network, with a CVSS score of 8.0. Microsoft patched the flaw on August 11, 2026, but Shadowserver Foundation scans show roughly 22,000 servers unpatched, with the US (6,200) and Germany (5,100) leading; BSI reports 85% of on-premises Exchange servers in Germany are still vulnerable. The Netherlands' NCSC-NL flagged that a working exploit is circulating, and Exchange 2016/2019 require the Extended Security Updates program for fixes.
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.