Chinese Hackers Exploit Critical Tencent Software Flaw for One-Click Code Execution

Chinese threat actors known as UNC3569 are actively exploiting a critical vulnerability in Tencent's Sogou Input Method to achieve one-click remote code execution. The exploit leverages CVE-2026-51990, chaining command-line injection with an unpatched Chromium 80 engine to deploy the GrayRabbit backdoor against victims. While the specific injection vector was fixed in version 16.3.0.3498, researchers note that the underlying browser engine remains vulnerable and unsandboxed.