CVE-2025-69517 is an HTML injection vulnerability identified in Amidaware Inc's Tactical RMM software, versions 1.3.1 and earlier. The flaw exists in the POST /api/v3/newagent/ endpoint, specifically in the agent_id parameter, which accepts up to 255 characters and is insufficiently sanitized. The sanitization relies on DOMPurify.sanitize() with the html:true option enabled, which inadvertently allows certain HTML content to bypass filters. As a result, an authenticated user can inject arbitrary HTML code during the creation of a new agent. This malicious HTML is later rendered within the Tactical RMM management panel when an administrator attempts to remove or shut down the compromised agent. The rendered malicious content can lead to client-side attacks such as UI manipulation, phishing, or potentially executing scripts that compromise the administrator's session or credentials. The vulnerability requires the attacker to have valid authentication credentials but does not require additional user interaction beyond the administrator viewing the affected agent. The CVSS v3.1 score of 8.8 reflects the high impact on confidentiality, integrity, and availability, with low attack complexity and no user interaction needed. Although no public exploits are currently known, the vulnerability poses a significant risk in environments where Tactical RMM is used for remote monitoring and management, especially given the privileged access of administrative users. The supplier has disputed some details of the vulnerability, but the technical risk remains substantial. No patches or mitigations have been officially released at the time of publication.

For European organizations, this vulnerability presents a critical risk due to the privileged nature of Tactical RMM, which is used to manage and monitor IT infrastructure remotely. Successful exploitation could lead to unauthorized access to administrative sessions, manipulation of the management interface, and potential phishing attacks targeting system administrators. This could result in the compromise of sensitive operational data, unauthorized changes to monitored systems, or disruption of IT services. Given the high CVSS score and the ability to affect confidentiality, integrity, and availability, organizations could face operational downtime, data breaches, and regulatory compliance issues under GDPR if personal or sensitive data is exposed. The requirement for authentication limits exposure to insider threats or compromised accounts, but the risk remains significant in environments with many users or weak credential management. Tactical RMM deployments in critical infrastructure sectors such as finance, healthcare, and government within Europe are particularly vulnerable to targeted attacks leveraging this flaw.

European organizations should immediately audit their Tactical RMM deployments to identify affected versions (1.3.1 and earlier). Since no official patches are currently available, organizations should implement compensating controls such as restricting access to the new agent creation API endpoint to only highly trusted users and monitoring for unusual agent creation activity. Administrators should be trained to recognize suspicious UI behavior in the management panel and avoid interacting with untrusted agents. Network segmentation and strict access controls should be enforced to limit exposure of the Tactical RMM interface. Implement multi-factor authentication (MFA) for all users with access to Tactical RMM to reduce the risk of credential compromise. Additionally, organizations should consider deploying web application firewalls (WAFs) with custom rules to detect and block suspicious HTML payloads in agent creation requests. Continuous monitoring and logging of administrative actions within Tactical RMM can help detect exploitation attempts. Finally, maintain close communication with Amidaware Inc for updates on official patches or security advisories.