TeamViewer Flaw Lets Remote Computers Attack Users Who Connect to Control Them

TeamViewer has patched a flaw that reverses the usual threat model in remote-support sessions: instead of the controlling machine endangering the target, the machine being controlled (the host) can attack the person who connected to manage it (the viewer). The bug, CVE-2026-111585, carries a severity score of 8.8 and affects TeamViewer Full Client on Windows, Linux, and macOS, the Windows Portable build, and the Android Remote Control app in all versions prior to 15.83 — including 15.82, released just last month. Researcher Omri Dar of Remedio found that a host can misreport its screen dimensions, causing the viewer to miscalculate a memory buffer and overflow it with incoming screen data; on Windows this was shown to bypass OS exploit protections and achieve arbitrary code execution, with no password or extra clicks required beyond joining the session. TeamViewer says it has no evidence of active exploitation and recommends all users update to version 15.83 or later, which also resolves two other high-severity bugs and accompanies a separate update, TV-2026-1012, fixing six issues in the Remote Management add-ons.