CVE-2026-20119 in RoomOS Software
Summary
by MITRE • 02/04/2026
A vulnerability in the text rendering subsystem of Cisco TelePresence Collaboration Endpoint (CE) Software and Cisco RoomOS Software could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on an affected device.
This vulnerability is due to insufficient validation of input received by an affected device. An attacker could exploit this vulnerability by getting the affected device to render crafted text, for example, a crafted meeting invitation. As indicated in the CVSS score, no user interaction is required, such as accepting the meeting invitation. A successful exploit could allow the attacker to cause the affected device to reload, resulting in a DoS condition.
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Analysis
by VulDB Data Team • 02/07/2026
The vulnerability identified as CVE-2026-20119 represents a critical weakness in the text rendering subsystem of Cisco TelePresence Collaboration Endpoint software and Cisco RoomOS software platforms. This flaw exists within the core processing mechanisms that handle text input and display operations, specifically affecting how these systems validate and process incoming textual data. The vulnerability stems from inadequate input sanitization and validation procedures that fail to properly examine or filter potentially malicious text content before rendering it on the device interface. This weakness creates a pathway for remote attackers to manipulate the device's text processing capabilities without requiring any form of authentication or user interaction.
The technical exploitation of this vulnerability occurs through the manipulation of text input parameters that the affected devices process during normal operation. Attackers can craft specially formatted text elements such as meeting invitations, calendar entries, or other textual content that, when processed by the vulnerable software, triggers unexpected behavior in the rendering subsystem. The flaw does not require any user action to be effective, making it particularly dangerous as it can be exploited silently in the background. When the malicious text is processed, the insufficient input validation causes the device to enter an abnormal state where it attempts to render the crafted content, leading to system instability and ultimately forcing the device to restart or reload its operating system.
The operational impact of this vulnerability extends beyond simple service disruption as it can effectively disable critical communication infrastructure within enterprise environments. Organizations relying on Cisco TelePresence systems for video conferencing, collaboration, and remote meeting capabilities face significant business continuity risks when this vulnerability is exploited. The automatic device reloading process creates extended downtime periods that can interrupt important meetings, collaborative sessions, and business operations. The vulnerability's remote exploitability means that attackers can target these devices from anywhere on the network without requiring physical access or network credentials, making it an attractive vector for malicious actors seeking to disrupt business operations or create cover for other attacks.
This vulnerability aligns with CWE-20, which describes "Improper Input Validation" as a fundamental weakness in software design that allows malicious inputs to bypass validation checks and cause system instability. From an adversarial perspective, this flaw maps to ATT&CK technique T1499.004, which covers "Endpoint Denial of Service" through the manipulation of device processes to cause system restarts or resource exhaustion. The lack of user interaction requirements makes this vulnerability particularly concerning from a security operations standpoint, as it can be exploited continuously without detection, potentially leading to repeated disruption events.
Organizations should implement immediate mitigations including firmware updates from Cisco to address the root cause of this vulnerability, network segmentation to limit access to affected devices, and monitoring of device behavior for unusual restart patterns. The remediation approach should focus on strengthening input validation mechanisms within the text rendering subsystem and implementing additional layers of protection such as network access controls that restrict unauthorized access to the affected systems. Regular security assessments of collaboration infrastructure should be conducted to identify similar vulnerabilities in other components of the communication ecosystem, as this represents a pattern of insufficient input validation that may exist in other parts of the software stack.