CVE-2025-43464 is a denial-of-service (DoS) vulnerability in Apple macOS identified as resulting from improper input validation (CWE-20). The vulnerability allows an attacker to cause an application on macOS to crash by enticing a user to visit a specially crafted malicious website. The root cause is insufficient validation of input data received from web content, which leads to an unexpected state causing the targeted application to become unresponsive or crash. This vulnerability does not compromise confidentiality or integrity but impacts availability by causing application downtime. The attack vector is network-based (AV:N), requiring no privileges (PR:N), but does require user interaction (UI:R) since the user must visit the malicious website. The scope is unchanged (S:U), meaning the impact is limited to the vulnerable application without affecting other system components. Apple addressed this issue in macOS Tahoe 26.1 by implementing improved input validation mechanisms to prevent malformed inputs from triggering the DoS condition. There are currently no known exploits in the wild, but the ease of exploitation and the potential for widespread impact on macOS users make timely patching critical. The CVSS v3.1 base score is 6.5, categorizing it as a medium severity vulnerability.

The primary impact of CVE-2025-43464 is denial of service, causing affected macOS applications to crash or become unresponsive when users visit malicious websites. This can disrupt user productivity and potentially affect business operations relying on those applications. While it does not lead to data breaches or privilege escalation, repeated or targeted exploitation could degrade user trust and system reliability. Organizations with macOS endpoints exposed to web browsing are at risk of service interruptions, especially in environments where critical applications run on macOS. The vulnerability could be leveraged in targeted attacks or as part of a broader disruption campaign. Since no authentication is required and exploitation only needs user interaction, the attack surface is broad. However, the lack of known exploits in the wild reduces immediate risk, though this may change if attackers develop reliable exploit code.

To mitigate CVE-2025-43464, organizations should prioritize updating all macOS systems to version Tahoe 26.1 or later, where the vulnerability is patched. Network-level protections such as web filtering and URL reputation services can help block access to known malicious websites that might exploit this vulnerability. Endpoint security solutions should be configured to detect and prevent anomalous application crashes or abnormal web content processing. User awareness training should emphasize caution when visiting untrusted websites to reduce the risk of triggering the DoS condition. Additionally, organizations can implement application whitelisting and sandboxing to limit the impact of any application crashes. Monitoring logs for unusual application failures can provide early detection of exploitation attempts. Since this vulnerability requires user interaction, reducing exposure to risky web content is a practical defense layer.