CVE-2026-34486: Apache Tomcat EncryptInterceptor Fail-Open Bypass
Technical analysis shows CVE-2026-34486 is a one-line fail-open regression in Tomcat Tribes enabling unauthenticated RCE via Java deserialization.
CVE-2026-34486 is a fail-open regression in Tomcat's Tribes EncryptInterceptor, introduced while fixing the CVE-2026-29146 padding-oracle flaw; Apache rated it Important and NVD scores it 7.5 High. Decryption failures are now forwarded to an unfiltered ObjectInputStream, and public PoC repositories demonstrate unauthenticated RCE on default port 4000 when clustering, the EncryptInterceptor, a reachable receiver and deserialization gadgets are all present. Affected releases 9.0.116, 10.1.53 and 11.0.20 are fixed in 9.0.117, 10.1.54 and 11.0.21; Tomcat 8.5 is unaffected.
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.
CISA Warns of Critical ScreenConnect Vulnerability Actively Exploited in Attacks
CISA added actively exploited ConnectWise ScreenConnect flaw CVE-2026-84869 to the KEV catalog, setting a September 14 patch deadline.
CISA added CVE-2026-84869, a critical improper privilege management and missing authorization flaw (CWE-269, CWE-862) in ConnectWise ScreenConnect, to its Known Exploited Vulnerabilities Catalog on September 11, 2026, confirming active exploitation. The flaw lets attackers transfer files to a device and execute them during an active remote ScreenConnect session without authorization or host-user confirmation, enabling payload delivery, unauthorized tools, and persistence while blending into legitimate remote-management traffic. CISA set a September 14 remediation deadline under BOD 26-04 and flagged the vulnerability as requiring forensic triage. ConnectWise has published a security bulletin, and defenders are urged to review exposure, sessions, file-transfer records, and outbound connections.
CVE-2026-85706: Critical GitLab Path Traversal Exploited in the Wild
CVE-2026-85706, a CVSS 10.0 unauthenticated path traversal in GitLab CE/EE, is actively exploited and was added to CISA's KEV catalog.
GitLab patched CVE-2026-85706, a critical path traversal (CWE-22) in the repository commits API scoring CVSSv3.1 10.0, allowing unauthenticated arbitrary file reads on affected self-managed servers under certain conditions. CISA added it to the KEV catalog on September 11, 2026, citing active exploitation, with a September 14 remediation deadline and BOD 26-04 forensic triage requirements. Fixed versions are 19.1.8, 19.2.6, and 19.3.2; the release also fixes 17 other vulnerabilities including CVE-2026-87719, a CVSS 9.9 insecure deserialization flaw in GitLab EE.
CISA Adds Exploited MikroTik RouterOS Flaws to Security Alert
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.
CISA Warns of Fortinet Heap-based Buffer Overflow Flaw Exploited in Attacks
CISA added actively exploited Fortinet CVE-2025-25249, a critical heap-based buffer overflow in FortiOS, FortiSwitchManager, and FortiSASE, to its KEV catalog.
CVE-2025-25249 is a heap-based buffer overflow (CWE-122/CWE-787) allowing unauthorized code execution by sending specially crafted packets. CISA added it to the Known Exploited Vulnerabilities catalog on September 9, 2026, with a September 12 remediation deadline for federal agencies under BOD 26-04 and mandatory forensic triage of affected environments. Internet-facing Fortinet firewalls and SASE platforms are a likely foothold for credential theft, persistence, and lateral movement; ransomware use is currently listed as unknown.
CVE-2026-34908: Ubiquiti Networks UniFi OS Server access control ...
CVE-2026-34908, a CVSS 10.0 access-control bypass in Ubiquiti UniFi OS, was added to CISA's KEV catalog amid reported active exploitation.
CISA added CVE-2026-34908 to the Known Exploited Vulnerabilities catalog on June 23, 2026, with remediation due June 26 under BOD 26-04 guidance. The CVSS 10.0 improper access control flaw (CWE-284) in Ubiquiti UniFi OS allows unauthorized system changes without authentication. Multiple news reports referenced by the page describe the max-severity UniFi flaws being exploited in attacks, and an official patch is available.
CVE-2026-16232: Checkpoint Quantum Security Management auth bypass ...
Attackers exploit Check Point SmartConsole authentication bypass CVE-2026-16232 to take over Quantum Security Management firewall servers; CISA added it to KEV.
CVE-2026-16232 is an authentication bypass (CWE-287) in the SmartConsole login process of Check Point Quantum Security Management, exploitable via an application token. Disclosed July 22, 2026, it was added to CISA's Known Exploited Vulnerabilities catalog the same day with remediation due July 25. Rapid7, Check Point Research and other vendors confirmed exploitation in the wild, and a public PoC was released. A workaround is available, and federal agencies must comply with BOD 26-04 patching guidance.
CVE-2026-16232: Check Point SmartConsole Auth Bypass
Check Point SmartConsole authentication bypass CVE-2026-16232 grants unauthenticated attackers full admin access; actively exploited and added to CISA KEV.
CVE-2026-16232 is an improper authentication flaw (CWE-287) in the Check Point SmartConsole login process that lets an unauthenticated remote attacker obtain an application token and authenticate with full administrative privileges. Exploitation requires the Management Server to be internet-reachable and the Trusted Clients list not restricted to specific administrator addresses. Check Point confirmed active exploitation affecting a small number of customers, and the vulnerability has been added to the CISA Known Exploited Vulnerabilities catalog. A hotfix is available via Check Point advisory sk185169.
CVE-2026-81578 + CVE-2026-82078 | PaperCut NG/MF Authentication Bypass and Unsafe Dynamic Class Loading Vulnerabilities
Two chained PaperCut NG/MF flaws, CVE-2026-81578 and CVE-2026-82078, enable pre-auth RCE, with active exploitation confirmed in customer environments.
PaperCut NG/MF is affected by CVE-2026-81578, an improper access control flaw (CVSS 4.0 8.8) allowing unauthenticated configuration changes, and CVE-2026-82078, an unsafe dynamic class loading flaw (CVSS 4.0 9.4) enabling arbitrary Java bytecode execution. Chained, they yield pre-authentication remote code execution on the PaperCut Application Server. PaperCut confirmed active exploitation and customer incidents, and Huntress observed exploitation starting August 26, 2026. Emergency Patch Release 2 is available for NG/MF v24-v26, with IOCs including suspicious pc-app.exe child processes, truncated server.log files, and AnyDesk installs.
CVE-2026-86218 | N-able N-central Pre-Authentication Remote Code Execution Vulnerability
N-able N-central pre-auth RCE CVE-2026-86218 (CVSS 10.0) is actively exploited; CISA added it to KEV and a hotfix is available.
CVE-2026-86218 is a critical pre-authentication remote code execution flaw (CWE-96 static code injection) in N-able N-central servers, scored 10.0 CVSS 4.0 by N-able and 9.8 CVSS 3.1 by NIST. N-able fixed it in N-central 2026.3 Hotfix 4 (build 2026.3.1.14) on September 5, 2026, and has already patched hosted NCOD environments. CISA added the CVE to its Known Exploited Vulnerabilities catalog on September 8, 2026, citing evidence of active exploitation, though researchers have not attributed every reported N-central compromise to this flaw. Horizon3 released a NodeZero Rapid Response test to validate exposure and recommends log review for prior compromise.
Critical Issabel PBX Command Execution Vulnerability Exploited in the Wild
Unauthenticated attackers exploit CVE-2026-89026 in Issabel PBX via forged JWT tokens to run OS commands; exploitation observed since September 9.
CVE-2026-89026 (CVSS v4 9.3) stems from a hard-coded HS256 JWT signing key in Issabel Framework's pbxapi/index.php, letting unauthenticated attackers forge bearer tokens and execute OS commands through the Asterisk Manager Interface originate endpoint. Issabel Framework versions before commit b97dbaf0b71c1c36f841e672b664afbeb02773bd are affected. Shadowserver Foundation first observed exploitation on September 9, 2026, and VulnCheck added the flaw to its Known Exploited Vulnerabilities database.