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Windows Defender ShieldCrash 0-Day Lets Attackers Read Arbitrary Files as SYSTEM

Unpatched Windows Defender zero-day 'ShieldCrash' PoC lets local attackers read arbitrary files as SYSTEM, apparently bypassing the CVE-2026-69414 patch.

Researcher MSNightmare published a skeleton proof-of-concept for 'ShieldCrash', an unpatched Microsoft Defender flaw enabling arbitrary file reads with SYSTEM privileges that reportedly persists on supported Windows versions after September 2026 updates. It appears to bypass the recent fix for the Malware Protection Engine elevation-of-privilege flaw CVE-2026-69414 (ShieldBreak), patched in engine version 1.1.26080.3. SYSTEM-level file disclosure could expose credentials, application secrets and registry hives and support post-compromise reconnaissance. No active exploitation is confirmed and Microsoft had issued no specific patch or mitigation at disclosure time.

GBHackersupdated · 5d agofirst · 6d agoExploit / PoC 7 sourcesCVE-2026-69414

One Click on a Malicious Link Lets Hackers Backdoor Sogou Input Method Users

Actively exploited one-click flaw in Sogou Input Method (CVE-2026-51990) let UNC3569 deploy the GRAYRABBIT espionage backdoor on Windows.

Gen Digital researchers found three weaknesses in Sogou Input Method's sgbiz protocol handler that chain into a one-click RCE running with the signed-in user's permissions. UNC3569 used the chain in an active intrusion, leveraging an unsandboxed Chromium 80 embedded browser, the known V8 flaw CVE-2021-38003, and DLL sideloading via 7-Zip to deploy the GRAYRABBIT backdoor. Tencent fixed the issue in version 16.3.0.3498 within 12 days of disclosure; Sogou is used by hundreds of millions of people, mainly in China.

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argument injection via the sgbiz: URI handler, unrestricted URL navigation in a CEF-based webview, and an unsandboxed outdated Chromium 80 engine to gain code execution and install the GrayRabbit backdoor.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

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.

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.