CVE-2025-1087 is a critical security vulnerability identified in Kong Inc.'s Insomnia desktop application, specifically in versions prior to 11.0.2. The vulnerability is classified under CWE-20 (Improper Input Validation) and CWE-94 (Improper Control of Generation of Code). It arises from insufficient validation of user-supplied input when processing template strings within the application. This flaw allows an attacker to inject malicious template code, leading to arbitrary JavaScript code execution in the context of the Insomnia application. Since Insomnia is a desktop application used primarily for API design, debugging, and testing, the execution of arbitrary code can compromise the confidentiality, integrity, and availability of the user's environment. The vulnerability is exploitable remotely without authentication (AV:N/PR:N), but requires user interaction (UI:A), such as opening a maliciously crafted template or project file. The CVSS 4.0 base score of 9.3 reflects the critical nature of this issue, with high impact on confidentiality, integrity, and availability, and a wide attack scope due to network accessibility and lack of privileges needed. Although no known exploits are currently reported in the wild, the potential for exploitation is significant given the ease of triggering the vulnerability through crafted input. The lack of a patch link suggests that users must upgrade to version 11.0.2 or later once available to remediate the issue. Overall, this vulnerability poses a severe risk to users of the Insomnia application, especially those handling sensitive API data or operating in environments where code execution could lead to broader system compromise.

For European organizations, the impact of CVE-2025-1087 can be substantial. Insomnia is widely used by developers and IT teams for API testing and development, meaning that exploitation could lead to unauthorized access to sensitive API credentials, tokens, or internal network information. This could facilitate further lateral movement within corporate networks or data exfiltration. The arbitrary code execution capability also raises the risk of malware deployment or ransomware attacks originating from a trusted application context. Given the criticality of API security in sectors such as finance, healthcare, and telecommunications—key industries in Europe—this vulnerability could disrupt services, violate data protection regulations like GDPR, and cause reputational damage. Additionally, since the attack requires user interaction, social engineering campaigns targeting European developers or IT staff could increase the likelihood of successful exploitation. The vulnerability's high severity and network attack vector make it a priority concern for organizations relying on Insomnia for API workflows.

European organizations should take immediate steps to mitigate this vulnerability beyond generic patching advice. First, ensure all instances of Insomnia are upgraded to version 11.0.2 or later as soon as the patch is available. Until then, restrict the use of Insomnia to trusted environments and avoid opening untrusted or unsolicited project files or templates. Implement application whitelisting and endpoint detection and response (EDR) solutions to monitor and block suspicious behaviors originating from Insomnia processes. Educate developers and IT staff about the risks of opening files from unknown sources and encourage verification of file origins. Network segmentation can limit the impact of a compromised endpoint by isolating API development environments from critical production systems. Additionally, review and tighten API credential management practices, including the use of short-lived tokens and multi-factor authentication, to reduce the risk of credential theft. Finally, monitor security advisories from Kong Inc. and subscribe to vulnerability feeds to stay informed about exploit developments and patch releases.