CVE-2025-29815 is a high-severity use-after-free vulnerability (CWE-416) identified in the Chromium-based Microsoft Edge browser, specifically affecting version 1.0.0.0. This vulnerability allows an authorized attacker to execute arbitrary code remotely over a network. Use-after-free vulnerabilities occur when a program continues to use memory after it has been freed, leading to undefined behavior such as memory corruption, crashes, or code execution. In this case, the flaw exists within Microsoft Edge's handling of certain objects or resources, which can be manipulated by an attacker to trigger execution of malicious code. The CVSS 3.1 base score of 7.6 reflects a high impact due to the vulnerability's ability to compromise confidentiality and integrity with relatively low attack complexity (AC:L), requiring only limited privileges (PR:L) and user interaction (UI:R). The scope remains unchanged (S:U), meaning the impact is confined to the vulnerable component. Although no known exploits are currently reported in the wild, the vulnerability is publicly disclosed and assigned a CVE identifier, indicating that attackers could develop exploits. The vulnerability is network exploitable (AV:N), making it a significant risk for users browsing malicious or compromised websites or receiving crafted content. The lack of available patches at the time of disclosure necessitates immediate attention to mitigation strategies to reduce exposure.

For European organizations, this vulnerability poses a substantial risk, especially for enterprises and government agencies relying on Microsoft Edge as their primary web browser. Successful exploitation could lead to unauthorized code execution, enabling attackers to steal sensitive data, install persistent malware, or disrupt operations. Given the widespread use of Microsoft Edge across corporate environments in Europe, the potential for lateral movement and escalation within networks is significant. Confidentiality and integrity of data are at high risk, while availability impact is lower but still present due to possible crashes or instability. The requirement for limited privileges and user interaction means targeted phishing or social engineering campaigns could be effective vectors. Sectors such as finance, healthcare, and critical infrastructure, which handle sensitive personal and operational data, are particularly vulnerable. Additionally, the network-based attack vector increases the threat surface, as attackers do not need physical access to systems. The absence of known exploits currently provides a window for proactive defense, but the public disclosure heightens the urgency for European organizations to act swiftly.

Beyond generic advice, European organizations should implement the following specific measures: 1) Enforce strict browser update policies to ensure rapid deployment of security patches once available from Microsoft. 2) Employ application control and whitelisting to restrict execution of unauthorized code and scripts within browser contexts. 3) Utilize network-level protections such as web filtering and intrusion prevention systems to block access to known malicious sites and detect exploit attempts targeting Edge. 4) Conduct targeted user awareness training emphasizing the risks of interacting with untrusted web content and the importance of cautious behavior to reduce user interaction exploitation. 5) Deploy endpoint detection and response (EDR) solutions capable of identifying anomalous behaviors indicative of use-after-free exploitation or post-exploitation activities. 6) Consider temporary use of alternative browsers with no known vulnerabilities until patches are released. 7) Monitor threat intelligence feeds and Microsoft advisories closely for updates on patches or exploit developments. 8) Implement strict privilege management to minimize the impact of compromised user accounts, limiting the attacker’s ability to escalate privileges or move laterally.