Vulnerabilities · 2h ago

TeamViewer flaw puts support technicians’ own machines at risk

Remedio disclosed CVE-2026-111585, an integer-overflow flaw in TeamViewer clients for Windows, macOS, Linux and Android that can let a malicious host execute code on a support technician’s machine. The attack requires the technician to join a remote-control session. TeamViewer says version 15.83 contains the patch, with updates also issued for legacy versions.

The host supplies its screen dimensions, and the client uses them to allocate memory for drawing incoming screen updates. An oversized value can make those updates write beyond that buffer; Remedio says a host can steer the client into this decoding path by declining video-codec negotiation. The result can be a crash or arbitrary code execution on the viewer’s system.

If a technician’s workstation can reach internal admin systems or hold useful credentials, a successful attack can extend a session against an outside host into the organization’s support access. The reporting does not establish whether the flaw has been exploited.

CVE-2026-111585

NVD KEV

CVSS 8.8 HIGH: an integer overflow in the remote-control screen processing component of TeamViewer clients (Full Client, Portable… EPSS 0.3% (21st percentile).

Timeline

Oct 30 Reported by SecurityWeek
Oct 28 Reported by CSIRT Italia / ACN

Sources

2 sources covering this story

SecurityWeek Oct 30
TeamViewer Flaw Could Let Malicious Hosts Take Over Support Technicians’ Machines
An integer overflow tracked as CVE-2026-111585 could be used to execute arbitrary code on the viewer’s system.
CSIRT Italia / ACN Oct 28
Risolte vulnerabilità in prodotti TeamViewer
TeamViewer ha rilasciato aggiornamenti di sicurezza per sanare 9 vulnerabilità con gravità “alta” in vari prodotti.

Entities

CVE-2026-111585

Part of the PlainSec briefing for 2026-10-30

Editions

Briefing for 2026-10-30

Vulnerabilities · 2h agoTeamViewer flaw puts support technicians’ own machines at riskRemedio disclosed CVE-2026-111585, an integer-overflow flaw in TeamViewer clients for Windows, macOS, Linux and Android that can let a malicious host execute code on a support technician’s machine. The attack requires the technician to join a remote-control session. TeamViewer says version 15.83 contains the patch, with updates also issued for legacy versions.The host supplies its screen dimensions, and the client uses them to allocate memory for drawing incoming screen updates. An oversized value can make those updates write beyond that buffer; Remedio says a host can steer the client into this decoding path by declining video-codec negotiation. The result can be a crash or arbitrary code execution on the viewer’s system.If a technician’s workstation can reach internal admin systems or hold useful credentials, a successful attack can extend a session against an outside host into the organization’s support access. The reporting does not establish whether the flaw has been exploited.

CVE-2026-111585

NVD KEV

CVSS 8.8 HIGH: an integer overflow in the remote-control screen processing component of TeamViewer clients (Full Client, Portable… EPSS 0.3% (21st percentile).