CVE-2026-12703

TeamViewer Full Client and Host for Linux prior to version 15.82 contain an improper path validation vulnerability in the Cloud Session Recording (CSR) functionality. By exploiting a race condition during path validation and subsequent file access, a local authenticated attacker may cause privileged file operations in unintended locations.

TeamViewer Full Client, Host, and related modules on Windows, Linux, and macOS contain an improper access control vulnerability. An authenticated remote attacker can bypass user-configured permission settings during session establishment by modifying access control parameters for restricted features. This may result in unauthorized actions and potentially lead to remote code execution.

TeamViewer Full Client and Host prior to version 15.82 on Windows contain a TOCTOU race condition in the installer rollback mechanism. A local low-privileged attacker can replace rollback backup files stored in a user-writable temporary directory before they are restored by an elevated installer, resulting in privilege escalation to NT AUTHORITY/SYSTEM.

TeamViewer Full Client and Host for Linux and macOS prior to version 15.82 contain a heap-based buffer overflow vulnerability in the processing of .tvs session recording files. A size mismatch during decompression of recorded session data can result in out-of-bounds heap writes. By convincing a user to open a specially crafted session recording through the "Play or convert recorded session…" feature, an attacker may achieve arbitrary code execution with the privileges of the current user.

Improper path validation in the local IPC service of TeamViewer Full Client and Host on Windows, Linux, and macOS prior to version 15.82 allows a local authenticated user with low privileges to perform arbitrary file writes with elevated privileges (NT AUTHORITY/SYSTEM \ root). By sending crafted IPC commands to the local service daemon, an attacker could manipulate file paths, leading to local privilege escalation.

A command injection vulnerability in TeamViewer Full Client and Host for Linux prior to version 15.81.5 allows a remote attacker to execute arbitrary commands in the context of the current user via a specially crafted URL sent through the out-of-session chat feature. Exploitation requires user interaction by clicking the malicious link.

Improper neutralization of path traversal sequences in TeamViewer Desktop Clients prior Version 15.81.5 allows an authenticated remote session participant to write files to unintended locations on the local file system via file transfer or virtual file clipboard mechanisms. An attacker can leverage this behavior to achieve arbitrary file write and potentially execute code with the privileges of the affected user.