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Rogue ScreenConnect Installations Across Unrelated Hosts Suggest Worm-Like Activity

Huntress observed rogue ScreenConnect deployments with worm-like VBScript propagation across unrelated organizations, prompting a ConnectWise advisory on file transfer behavior.

Huntress identified multiple incidents in late August 2026 where social engineering led to rogue ScreenConnect remote access clients deployed on victim machines, which then spawned wscript.exe to run four VBScript payloads (1.vbs through 4.vbs) for profiling, telemetry collection, and persistence via a WindowsServiceHost Run key. Modified ScreenConnect clients propagated the VBScript chain to connected endpoints, creating worm-like spread. ConnectWise published an advisory on September 3, 2026, confirming an issue affecting file transfer behavior in both cloud and on-premises ScreenConnect deployments, with a CVE and fix expected within the week; partners were advised to review and disable TransferFiles permissions in the interim.

Huntress · 13d agoExploit / PoC in the wild1

Hackers exploit Tencent app flaw to deploy GrayRabbit malware

UNC3569 actively exploits one-click RCE in Tencent Sogou Input Method to deploy the GrayRabbit backdoor, patched in version 16.3.0.3498.

Gen Digital reports that China-aligned UNC3569 is actively exploiting CVE-2026-51990, a one-click RCE chain in Tencent Sogou Input Method for Windows, which has hundreds of millions of installations in China. The chain abuses unvalidated command-line argument injection via the sgbiz: URI handler, unrestricted URL navigation in a CEF-based webview, and an unsandboxed outdated Chromium 80 engine to gain code execution and install the GrayRabbit backdoor. The analyzed malware is a mature 64-bit variant with RC4-encoded C2 config supporting reverse shells, file transfer, and reflective plugin loading. Tencent patched the argument validation in version 16.3.0.3498, but the browser engine remains outdated and unsandboxed.

BleepingComputerupdated · 1d agofirst · 2d agoExploit / PoC in the wild 2 sourcesCVE-2026-519903

Chaotic Eclipse Released GreenSection, A PoC For NVIDIA Memory Corruption Zero-Day

Researcher Chaotic Eclipse released GreenSection, a PoC exploiting an unpatched out-of-bounds write in NVIDIA Windows user-mode shared memory.

Security researcher Chaotic Eclipse disclosed an out-of-bounds write in NVIDIA's Windows user-mode components, which share a global memory section (\BaseNamedObjects\{52813408-3561-4705-820a-2b3b78be92ba}) with full read/write access to all users. The PoC crashes applications running Vulkan or OpenGL; the researcher says the bug could cross user boundaries or compromise dwm.exe but did not fully assess the impact. No CVE has been assigned and no patch is mentioned. The researcher recently released zero-day PoCs against Kaspersky, Avast, and CrowdStrike Falcon.

Security Affairs · 8d agoExploit / PoC 2 sources

Human Attacker Exploits Marimo RCE, Reaches SSH Bastion in Eight Seconds

Sysdig documents a skilled human attacker exploiting Marimo pre-auth RCE CVE-2026-39987 (CVSS 9.3), reaching an SSH bastion in eight seconds without AI tooling.

Sysdig detailed exploitation of CVE-2026-39987 (CVSS 9.3), a pre-authenticated RCE affecting all Marimo versions that came under active exploitation within hours of disclosure. A human operator used a hand-written Python script to harvest an AWS key from Secrets Manager and SSH into a bastion host in eight seconds, issuing 850+ commands over nine hours. Separately, Hunt.io disclosed an XMRig cryptomining campaign compromising 3,562 Redis servers via SLAVEOF rogue replication and AOF authorized_keys injection. Operation CameraSwarm, linked to a single operator, compromised over 14,000 Dahua IP cameras using CVE-2021-33044 and CVE-2021-33045.

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.

Threat Brief: OWASSRF Vulnerability Exploitation

Unit 42 details active exploitation of Exchange SSRF flaws CVE-2022-41080/CVE-2022-41082 via the OWASSRF method, deploying the SilverArrow PowerShell backdoor.

Unit 42 documents OWASSRF, an exploit chain combining CVE-2022-41080 and CVE-2022-41082 to achieve remote code execution on Microsoft Exchange via Outlook Web Access, bypassing Microsoft's ProxyNotShell mitigations. Active exploitation was observed in late November and early December 2022, affecting at least eight organizations. Attackers authenticated to Exchange, then executed a PowerShell backdoor tracked as SilverArrow to create admin accounts, install AnyDesk, tunnel RDP via PuTTY Link, and dump LSASS memory for credential theft. Exploitation is isolated rather than mass-scale because authentication is required.

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.