Fortinet has confirmed a critical zero-day vulnerability; the available headline provides no product, CVE, or exploitation details.
Infosecurity Magazine's headline states that Fortinet has confirmed a critical zero-day vulnerability. The available source text contains no additional details on affected products, CVE identifiers, exploitation status, or available fixes. Defenders should treat specifics as unconfirmed pending a vendor advisory.
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.
Cisco warns CVE-2026-76461 in Secure Email Gateway AsyncOS is actively exploited, letting unauthenticated attackers run root commands via crafted emails.
Cisco disclosed CVE-2026-76461, a CVSS 9.8 flaw in AsyncOS for Cisco Secure Email Gateway caused by insufficient validation in email parsing, allowing unauthenticated remote attackers to execute arbitrary SQL statements leading to root command execution. Active exploitation began in September 2026, and CISA added the flaw to its KEV catalog, requiring FCEB agencies to patch by September 17, 2026. Fixes are available in AsyncOS 15.5.5-0141, 16.0.4-302, and 16.5.0-780, with no workarounds. Cisco also contacted Secure Email Cloud customers where malicious activity was detected, and the article separately notes large-scale credential attacks on Fortinet VPN appliances generating tens of millions of authentication failures.
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.
CISA added four actively exploited vulnerabilities—Fortinet buffer overflow, Citrix NetScaler and Cisco auth bypasses, and a Chromium V8 write—to the KEV Catalog.
CISA added CVE-2025-25249 (Fortinet heap-based buffer overflow), CVE-2026-19490 (Citrix NetScaler authentication bypass), CVE-2026-87491 (Google Chromium V8 out-of-bounds write), and CVE-2026-20079 (Cisco Firewall Management Center authentication bypass) to its Known Exploited Vulnerabilities Catalog based on evidence of active exploitation. Under Binding Operational Directive 26-04, Federal Civilian Executive Branch agencies must prioritize rapid remediation of these high-risk vulnerabilities on exposed assets and verify whether systems were compromised before patching. CISA encourages all organizations to adopt risk-based vulnerability management and prioritize KEV Catalog remediation.
Attackers actively exploit CVE-2025-25249 in FortiGate firewalls to deploy PivotC2, a Node.js RAT that decrypts VPN and admin credentials.
SOCRadar assesses with high confidence that threat actors are actively exploiting CVE-2025-25249, a CVSS 9.8 heap buffer overflow in the cw_acd daemon (CAPWAP, UDP 5246) affecting FortiOS 6.4-7.6.3 and FortiSwitchManager 7.0.x/7.2.x. Attackers deploy fortirun.bin and PivotC2, a Node.js post-exploitation framework that harvests configurations and decrypts SSL-VPN, wireless, and admin credentials using AES-256-CBC and AES-128-GCM. Over 30,000 FortiGate IPs were scanned and 178 devices compromised, including two confirmed full intrusions of US organizations with Exchange mailbox exfiltration to Wasabi storage. STRU attributes the campaign to a Russian-speaking, financially motivated cybercrime operator.