CVE-2026-111585 in TeamViewer
Summary
by MITRE • 10/27/2026
An integer overflow in the remote-control screen processing component of TeamViewer clients (Full Client, Portable and Remote Control App) prior to version 15.83 may allow a malicious remote host to cause a denial of service or, depending on the platform, potentially execute arbitrary code with the privileges of the viewer process. Exploitation requires a user to establish a remote-control session to an attacker-controlled or compromised host.
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Analysis
by VulDB Data Team • 10/27/2026
The vulnerability identified in TeamViewer clients prior to version 15.83 represents a critical security flaw rooted in improper integer handling within the remote-control screen processing component. This specific defect, classified under CWE-190 as Integer Overflow or Wraparound, occurs when the application fails to correctly validate arithmetic operations related to memory allocation or buffer sizing during the rendering of remote desktop sessions. When a malicious actor controls the host side of a connection, they can craft specific data packets that trigger this overflow condition. The core technical issue lies in the failure to check for integer overflows before performing calculations that determine the size of buffers used to store screen capture data. This lack of validation allows an attacker to manipulate internal variables such that the calculated buffer size wraps around or becomes significantly smaller than intended, leading to a mismatch between allocated memory and actual data requirements.
The operational impact of this vulnerability is severe due to its potential for both denial of service and arbitrary code execution. In scenarios where the integer overflow results in insufficient memory allocation relative to the input data, the application may write beyond the bounds of the allocated buffer. This out-of-bounds write can corrupt adjacent memory structures, potentially overwriting critical control data such as function pointers or exception handlers on stack-based platforms. Such corruption enables an attacker to redirect program execution flow, thereby achieving arbitrary code execution with the privileges of the viewer process. On other platforms where immediate exploitation for code execution is not feasible due to mitigations like DEP or ASLR, the memory corruption can still cause instability within the application, leading to a crash and resulting in a denial of service condition that disrupts remote support operations.
Exploitation of this vulnerability requires social engineering elements combined with technical setup, specifically necessitating that a user initiates a remote-control session connecting to an attacker-controlled or compromised host machine. The victim must actively grant control permissions to the malicious entity, which serves as the primary vector for delivering the exploit payload. Once the connection is established and the vulnerable screen processing component begins handling the incoming data stream from the hostile host, the crafted integer overflow triggers automatically during normal session operations. This requirement means that while the vulnerability itself is high-severity due to its potential impact, it relies on user interaction or a pre-existing compromise of the remote endpoint to be successfully leveraged against an unpatched client system.
To mitigate this risk, organizations and individual users must prioritize immediate patching by upgrading TeamViewer clients, including Full Client, Portable versions, and Remote Control Apps, to version 15.83 or later where these integer validation checks have been implemented. Beyond software updates, defensive strategies should include restricting remote access permissions to trusted entities only and implementing network-level controls that monitor for anomalous data patterns in RDP-like traffic if applicable. Security teams should also enforce strict application whitelisting policies to limit the execution of untrusted binaries and ensure that endpoint detection and response solutions are configured to detect memory corruption anomalies indicative of exploitation attempts related to CWE-190. This approach aligns with ATT&CK techniques involving remote service exploits, emphasizing the need for robust patch management and least privilege principles in environments relying on remote support tools.