CVE-2025-13026 is a critical security vulnerability identified in Mozilla Firefox and Thunderbird versions earlier than 145. The flaw resides in the Graphics: WebGPU component, where incorrect boundary conditions lead to a sandbox escape (CWE-703). Sandboxing is a key security mechanism designed to isolate potentially malicious code and prevent it from affecting the host system. This vulnerability allows an attacker to bypass these sandbox restrictions, enabling arbitrary code execution with the privileges of the user running the browser or email client. The vulnerability is remotely exploitable without any authentication or user interaction, making it highly dangerous. The CVSS v3.1 base score is 9.8, reflecting the vulnerability's high impact on confidentiality, integrity, and availability. Although no exploits have been observed in the wild yet, the nature of the flaw and the widespread use of Firefox and Thunderbird make it a prime target for attackers. The vulnerability affects all Firefox and Thunderbird versions prior to 145, but specific affected versions are unspecified. The WebGPU API is a modern graphics API designed to provide high-performance GPU access in web applications, and its complexity may contribute to the boundary condition errors. This vulnerability could allow attackers to execute malicious code, steal sensitive information, or disrupt services by crashing or corrupting the affected applications.

For European organizations, the impact of CVE-2025-13026 is substantial. Firefox is one of the most widely used browsers in Europe, and Thunderbird remains popular for email communications in many enterprises and government agencies. A successful exploit could lead to full compromise of user systems, data breaches, and disruption of critical services. Confidential information handled through browsers or email clients could be exposed or manipulated. The vulnerability's ability to execute code without user interaction or authentication increases the risk of automated mass exploitation campaigns. Critical sectors such as finance, healthcare, government, and energy, which rely heavily on secure communications and web access, could face operational disruptions and regulatory consequences. Additionally, the potential for lateral movement within networks after initial compromise could escalate the threat to organizational infrastructure.

Immediate mitigation should focus on disabling the WebGPU feature in Firefox and Thunderbird if patching is not yet available, as this component is the root cause of the vulnerability. Organizations can configure browser policies or use enterprise management tools to disable WebGPU. Network-level controls should be implemented to restrict outbound and inbound traffic to known safe destinations, reducing exposure to remote exploitation attempts. Endpoint detection and response (EDR) solutions should be tuned to detect anomalous behaviors related to sandbox escapes or unusual GPU API calls. Users and administrators must monitor Mozilla security advisories closely and apply official patches as soon as they are released. Additionally, organizations should conduct awareness training to inform users about the risks of visiting untrusted websites or opening suspicious emails, which could trigger exploitation attempts. Regular vulnerability scanning and penetration testing can help identify unpatched systems and assess exposure.