CVE-2026-1181 is a critical security vulnerability identified in Altium 365, a cloud-based workspace platform widely used for electronic design automation. The root cause is an overly permissive Cross-Origin Resource Sharing (CORS) configuration on Altium 365 workspace endpoints. Specifically, the CORS policy allows credentialed cross-origin requests from other subdomains controlled by Altium, including forum.live.altium.com. This means that JavaScript code executing on these trusted subdomains can make authenticated API calls to the workspace endpoints, inheriting the privileges of the logged-in user. The vulnerability is classified under CWE-942 (Permissive Cross-domain Policy with Untrusted Domains) and CWE-284 (Improper Access Control). The risk escalates when this permissive CORS policy is chained with vulnerabilities in the external applications hosted on these subdomains, enabling attackers to bypass IP allowlisting controls and perform unauthorized administrative actions. This is particularly concerning for GovCloud environments, which are designed for sensitive government data and require strict access controls. The vulnerability affects confidentiality by exposing sensitive workspace data, integrity by allowing unauthorized administrative changes, and availability by potentially disrupting workspace services. The CVSS v3.1 score of 9.0 reflects the critical nature of the vulnerability, with network attack vector, low attack complexity, required privileges, user interaction, and scope change. No public exploits have been reported yet, but the potential impact is severe.

For European organizations, especially those in sectors such as aerospace, defense, government, and critical infrastructure that rely on Altium 365 for electronic design and collaboration, this vulnerability poses a significant risk. Unauthorized access to workspace data could lead to intellectual property theft, exposure of sensitive design documents, and compromise of proprietary information. Administrative control bypass could allow attackers to alter configurations, disrupt workflows, or exfiltrate data. The ability to bypass IP allowlisting undermines network perimeter defenses, increasing the attack surface. Organizations operating in regulated environments, including those complying with GDPR and other data protection laws, could face legal and financial repercussions if sensitive data is compromised. The presence of this vulnerability in GovCloud environments further elevates the risk for government contractors and agencies in Europe. Additionally, the trust model between subdomains is exploited, which may affect the overall security posture of organizations relying on integrated Altium services. The lack of known exploits in the wild suggests an opportunity for proactive mitigation before widespread exploitation occurs.

European organizations using Altium 365 should immediately audit and restrict the CORS policies on their workspace endpoints to only allow trusted origins with a strict validation mechanism, avoiding wildcard or broad subdomain allowances. They should verify and harden the security posture of all Altium-controlled subdomains, such as forum.live.altium.com, ensuring no additional vulnerabilities exist that could be chained with this issue. Implement Content Security Policy (CSP) headers to limit the execution of untrusted scripts. Review and tighten IP allowlisting configurations and consider additional network segmentation to reduce exposure. Employ multi-factor authentication and monitor API access logs for anomalous or unauthorized activities. Engage with Altium support or security advisories to obtain patches or updates once available. Conduct internal penetration testing focusing on cross-origin interactions and privilege escalation scenarios. Finally, educate users about the risks of interacting with potentially compromised subdomains and enforce least privilege principles for workspace access.