Chinese Hackers Exploit Critical Tencent Software Flaw for One-Click Code Execution
Source SecurityWeek
Not known to be exploited · CVSS 9.8 Critical.
Data as of 29 Oct 2026, 19:04 UTC
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:HExploitation evidence
Disclosed: evidence found.
CVE published 16 Sep 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 29 Oct 2026.
What to do
AI-suggested
Tencent released an official patch in Sogou Input Method version 16.3.0.3498 that adds validation checks for URL parameters in the protocol handler, mitigating the command-line argument injection vector. Users should ensure they have updated to this version or later via the automatic update mechanism. However, the underlying Chromium browser engine remains outdated and unpatched, so additional mitigations may be limited. No further vendor advisories indicate additional fixes or mitigations. Patch status is confirmed as fixed for the URL parameter validation issue; users should apply the update promptly.
Description
A critical vulnerability (CVE-2026-51990) in Tencent's Sogou Input Method for Windows has been exploited by the Chinese threat group UNC3569 to achieve system-level code execution via a crafted URL. The flaw involves unvalidated command-line argument injection, unrestricted URL navigation, and an outdated Chromium browser engine with disabled sandboxing. The exploit enables deployment of the GrayRabbit backdoor, which provides extensive remote control capabilities. Tencent released a patch in version 16.3.0.3498 that addresses the URL parameter validation but did not update the underlying Chromium configuration. The vulnerability has been actively exploited in the wild.