Weekly Cybersecurity Newsletter Bulletin – Microsoft 0-day, FortiOS, PAN-OS Flaw, Revolut Data Breach, and 20+ Stories
Weekly roundup: Microsoft patches 973 flaws including two actively exploited zero-days; FortiOS CAPWAP flaw deploys PivotC2 RAT; PAN-OS root RCE disclosed.
Microsoft's September 2026 Patch Tuesday fixed 973 vulnerabilities, including two zero-days under active exploitation: CVE-2026-85880 (Windows ALPC) and CVE-2026-81963 (Windows Update Stack), both elevation-of-privilege bugs. SOCRadar reported active exploitation of CVE-2025-25249 (CVSS 9.8) in FortiOS CAPWAP, deploying a Node.js RAT called PivotC2 that exfiltrates Exchange mailboxes to Wasabi cloud storage; 178 devices were compromised out of 30,000 scanned IPs, attributed to a Russian-speaking financially motivated group. Palo Alto disclosed CVE-2026-0310, a 9.2-rated buffer overflow enabling root code execution on PA-Series firewalls, and Fortinet disclosed CVE-2026-84393, a ZTNA certificate validation MITM flaw. Cyera also revealed CVE-2026-6471 ('PostGREShell'), a 12-year-old PostgreSQL logical-decoding flaw allowing code execution via REPLICATION-privileged accounts.
BGP hijack infecting networks caused by a comedy of errors that’s not funny at all
Attackers BGP-hijacked Softaculous IP space via Hetzner routing lapses to push malicious Virtualizor updates to hosting servers.
Unknown attackers hijacked the 162.55.80.0/24 prefix used by Softaculous' Virtualizor update service by abusing lax routing security at hosting provider Hetzner Online, announcing the range through AS6204, AS62390, and AS24940 with a forged but RPKI-valid origin. The hijack pulsed intermittently over roughly 33 hours, delivering modified update packages to Virtualizor servers, which lacked cryptographic code signing for updates. Softaculous says only a small number of servers were likely affected but cannot produce a definitive list, urging administrators to treat every Virtualizor server as in scope for checks.
Week in review: Palo Alto Networks firewalls under attack, Microsoft patches two exploited zero-days
Google Chrome 153 Released With 230 Security Fixes and Zero-Day Exploited in the Wild
Google released Chrome 153 with 230 security fixes, patching CVE-2026-87491, a V8 out-of-bounds write zero-day actively exploited in the wild.
Google shipped Chrome 153 (153.0.8010.36/.37) for Windows, macOS, and Linux with 230 security fixes, including CVE-2026-87491, a medium-severity V8 out-of-bounds write being exploited in the wild. The release also fixes five critical vulnerabilities: four in WebGL (two use-after-frees, an out-of-bounds write, a buffer overflow) and one use-after-free in Cast. High-severity V8 use-after-free and type-confusion defects are among the fixes, and Google has restricted technical details until most users are patched. Administrators should verify deployed versions on managed endpoints, as Chrome-derived browsers may follow different patch schedules.
BGP Hijack Delivers Malicious Virtualizor Update That Establishes Persistent Root Access
Attackers used a BGP hijack to divert Softaculous traffic and push a malicious Virtualizor update granting root persistence on some hypervisors.
Virtualizor reported that a BGP hijack between August 28 20:57 UTC and August 30 06:10 UTC diverted Softaculous update traffic to an attacker-operated server holding a valid Let's Encrypt certificate. Installations checking for updates during the window could receive a malicious package that added an attacker SSH key to root, created a proxyuser account, and installed a Java payload persisted via a systemd service. Hosting provider AlbaHost confirmed 5 of its 34 Virtualizor hypervisors were root-compromised. Virtualizor shipped Patch 9 with a Security Analyzer on September 1, but cryptographic package signing remains future work.
Hackers Exploit FortiGate SSL-VPN Vulnerability to Attack Broadband Provider
Exposed attacker staging server reveals intrusion of Thai broadband provider 3BB via actively exploited FortiGate SSL-VPN flaw CVE-2024-21762.
Hunt.io found an open directory on server 92.63.180[.]133 holding 298 files detailing an intrusion into Triple T Broadband's 3BB brand, starting from a FortiGate 60F SSL-VPN at mail.3bb.co[.]th:10443. The actor weaponized CVE-2024-21762 (CVSS 9.8, KEV-listed since February 2024) using heap spraying and a ROP chain to gain a reverse shell. Post-exploitation included MeshCentral root-level persistence via www.ayuthayatech[.]com, Dirty COW/PwnKit privilege escalation, credential harvesting, SSH spraying against 55+ internal addresses, and log-deleting cleanup scripts; a stolen OpenVPN certificate and key from Triple T's PKI may still be valid.
Hackers exploit RouterOS flaws to hijack MikroTik devices without authentication
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.
U.S. CISA adds Apple macOS, Microsoft SharePoint, Broadcom VMware vCenter, and Microsoft IKE flaws to its Known Exploited Vulnerabilities catalog
CISA adds actively exploited flaws in Microsoft IKE, SharePoint, VMware vCenter, and macOS Screen Sharing to KEV catalog, due August 21.
CISA added four vulnerabilities to its Known Exploited Vulnerabilities catalog: CVE-2026-33824 (Windows IKE remote code execution, CVSS 9.8), CVE-2026-55040 (SharePoint JWT authentication bypass, CVSS 9.1), CVE-2026-59310 (VMware vCenter Syslog path traversal, CVSS 9.8), and CVE-2026-65400 (macOS Screen Sharing improper authentication). The SharePoint flaw combines four weaknesses including alg:none JWT forging to impersonate any user, with Defused researchers observing attackers using Rapid7's PoC against honeypots. The Dutch NCSC confirmed active exploitation of the macOS Screen Sharing flaw on August 15, 2026. Federal agencies must patch by August 21, 2026.
SharePoint CVE-2026-55040 Comes Under Attack Following Public Exploit
Attackers are actively exploiting critical SharePoint authentication bypass CVE-2026-55040 (CVSS 9.1) days after Rapid7 released a public PoC.
CVE-2026-55040 is a critical authentication bypass (CVSS 9.1) in SharePoint Server Subscription Edition that lets unauthenticated attackers forge JWT tokens and impersonate any user, including administrators. Microsoft patched it in July 2026 Patch Tuesday, but Rapid7 published a technical write-up and Python PoC on GitHub on August 12, and Defused quickly observed attackers running the PoC against SharePoint honeypots. KEVIntel recorded 12 exploitation attempts since July 19, with eight occurring on August 12-13 from IP addresses in Hong Kong, Japan, the Netherlands, Taiwan and the U.S. Admin-level SharePoint access exposes documents and data modification and can serve as a foothold into broader Microsoft 365 infrastructure; unpatched instances should apply the July update immediately.