CVE-2025-59251 is a stack-based buffer overflow vulnerability classified under CWE-121, affecting Microsoft Edge (Chromium-based) version 1.0.0.0. This vulnerability allows remote code execution (RCE) by an attacker who can send crafted network requests that trigger the buffer overflow condition. The flaw arises from improper bounds checking in Edge's code, enabling an attacker to overwrite the stack and execute arbitrary code. The CVSS 3.1 vector (AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:L/RC:C) indicates that the attack can be performed remotely over the network with low complexity, requires limited privileges, and user interaction, and affects confidentiality and integrity severely while having a low impact on availability. The vulnerability is currently published but lacks publicly known exploits, suggesting it is either newly discovered or not yet weaponized. The vulnerability also relates to CWE-94, which involves improper control of code generation, indicating potential code injection or execution risks. Since the affected version is 1.0.0.0, it likely impacts early or initial releases of Microsoft Edge Chromium-based browsers. The vulnerability's exploitation could allow attackers to run malicious code in the context of the user, potentially leading to data theft, system compromise, or lateral movement within networks.

For European organizations, this vulnerability poses a significant risk to confidentiality and integrity of sensitive data accessed or processed via Microsoft Edge. Organizations in sectors such as finance, healthcare, government, and critical infrastructure could face data breaches or operational disruptions if exploited. The requirement for user interaction means phishing or social engineering could be vectors, increasing the risk in environments with less user awareness training. The low availability impact suggests that denial-of-service is less likely, but the potential for remote code execution means attackers could establish persistent footholds or deploy ransomware. Given Microsoft Edge's widespread adoption in Europe, especially in enterprise environments, the vulnerability could facilitate targeted attacks against high-value assets. The absence of known exploits currently provides a window for proactive mitigation, but the high CVSS score underscores urgency in patching and defense.

1. Immediately inventory and identify all systems running Microsoft Edge Chromium-based version 1.0.0.0 and restrict their use until patched. 2. Monitor Microsoft security advisories closely for official patches or updates addressing CVE-2025-59251 and apply them promptly once available. 3. Employ application control policies to restrict execution of unauthorized or outdated browser versions. 4. Enhance endpoint detection and response (EDR) capabilities to detect anomalous behaviors indicative of exploitation attempts, such as unusual memory operations or code injection patterns. 5. Conduct user awareness training focused on phishing and social engineering to reduce the likelihood of user interaction exploitation. 6. Use network-level protections such as web filtering and intrusion prevention systems (IPS) to block malicious payloads targeting Edge vulnerabilities. 7. Consider deploying browser isolation or sandboxing technologies to limit the impact of potential exploitation. 8. Regularly review and update privilege management policies to minimize the privileges of users running Edge, reducing the impact of exploitation.