Security Advisory Desk
mediumQCS priority 82/100Cisco

Cisco RoomOS Stack Overflow Vulnerability

A flaw in the USB driver of Cisco RoomOS devices lets someone with physical access to the USB port run harmful software with the highest system privileges. They do this by plugging in a malicious USB device, which exploits a coding error to take control. Cisco has fixed this in updated software, but currently, there are no other ways to avoid this risk except updating.

Published 19/8/2026, 4:00:00 pmVerified 19/8/2026, 7:21:55 pmRevision 1
Cisco medium network security advisory visual

In plain language

What this advisory means

A flaw in the USB driver of Cisco RoomOS devices lets someone with physical access to the USB port run harmful software with the highest system privileges. They do this by plugging in a malicious USB device, which exploits a coding error to take control. Cisco has fixed this in updated software, but currently, there are no other ways to avoid this risk except updating.

Technical explanation

How the issue affects the environment

The vulnerability in Cisco RoomOS's USB driver is caused by insufficient boundary checks on data input from USB devices. This lack of validation leads to a buffer overflow condition. An unauthenticated local attacker with physical access can exploit this by connecting a malicious USB device, triggering the overflow to execute arbitrary code with root privileges. The flaw is identified as CWE-120 and tracked as CVE-2026-20302. Cisco has released fixed software versions to remediate this issue, but no workarounds are available.

Operational impact

Why teams should care

This vulnerability allows attackers with physical access to gain root-level control over affected Cisco RoomOS devices. Such unauthorized access can lead to complete system compromise, data breaches, service disruption, and increased risk to organizational network security. Since there are no workarounds, organizations must promptly update software to mitigate this risk and protect their critical collaboration infrastructure.

Immediate action

Cisco strongly recommends upgrading affected Cisco RoomOS devices to the fixed software releases indicated in the advisory to fully remediate the vulnerability and prevent exploitation.

Affected and fixed releases

Affected versionsCisco RoomOS 11 and earlier releases
Fixed versionsCisco RoomOS 11.32.7.0 and later for on-premises operation, Cisco RoomOS 11.40.1.1 and later for cloud-aware operation

Temporary risk reduction

There are no workarounds available for this vulnerability. The only effective remediation is applying the software update provided by Cisco.

Evidence and validation checklist

  • CVE identifier CVE-2026-20302 assigned by Cisco PSIRT
  • Official Cisco Security Advisory published on August 19, 2026
  • Description of vulnerability in USB driver due to insufficient boundary checks causing buffer overflow
  • Physical access required to USB port for local attacker to exploit
  • No workarounds available according to advisory
  • Fixed software versions provided by Cisco for affected RoomOS versions
  • Medium severity impact rating by Cisco

Authoritative reference

Cisco PSIRT Advisories

QCS detected and normalized this record from the official source. Vendor guidance remains authoritative.

Open source