CVE-2025-13158 is a prototype pollution vulnerability classified under CWE-1321, affecting the apidoc-core library starting from version 0.2.0. Prototype pollution occurs when an attacker can manipulate the prototype of a base object in JavaScript, thereby altering the behavior of all objects inheriting from that prototype. In this case, the vulnerability resides in the preProcess() function within several worker modules (api_group.js, api_param_title.js, api_use.js, and api_permission.js). The vulnerability arises because the application processes malformed data structures that include a 'define' property, which can be crafted by an attacker to inject or modify properties on the Object prototype. This can lead to widespread side effects such as denial of service (application crashes or infinite loops), data corruption, or execution of unintended logic paths in applications relying on apidoc-core for API documentation generation or processing. The vulnerability is remotely exploitable without any authentication or user interaction, increasing its risk profile. The CVSS 4.0 score of 9.3 reflects the ease of exploitation (network vector, low attack complexity), no privileges or user interaction needed, and a high impact on confidentiality, integrity, and availability. Although no public exploits are currently known, the critical severity demands urgent attention from developers and organizations using apidoc-core. The lack of available patches at the time of disclosure means that mitigation must focus on input sanitization and restricting prototype modifications until an official fix is released.

For European organizations, the impact of CVE-2025-13158 can be significant, especially those involved in software development, API documentation, and automation relying on apidoc-core. Exploitation could lead to denial of service, disrupting development pipelines and potentially delaying product releases. More critically, prototype pollution can cause unpredictable application behavior, which might introduce security flaws or data integrity issues in downstream applications that consume the documentation or metadata generated by apidoc-core. This could indirectly expose sensitive information or allow further exploitation in complex supply chains. Organizations in sectors such as finance, healthcare, and critical infrastructure, which often have stringent compliance requirements, could face regulatory and operational risks if this vulnerability is exploited. The remote and unauthenticated nature of the attack vector increases the threat surface, making it easier for attackers to target exposed development environments or CI/CD systems. Additionally, the widespread use of JavaScript and Node.js in European tech ecosystems amplifies the potential reach of this vulnerability.

1. Immediately audit all usage of apidoc-core in development and production environments to identify affected versions (0.2.0 and later). 2. Implement strict input validation and sanitization on all data fed into apidoc-core, particularly scrutinizing any user-controllable or external inputs that could influence the 'define' property or other prototype-related fields. 3. Employ JavaScript security best practices such as freezing Object prototypes (e.g., Object.freeze(Object.prototype)) to prevent unauthorized modifications. 4. Isolate the apidoc-core processing environment to minimize impact scope, for example by running it in sandboxed containers or restricted CI/CD agents. 5. Monitor application logs and runtime behavior for anomalies indicative of prototype pollution, such as unexpected property changes or crashes. 6. Engage with the apidoc-core maintainers for patches or updates and apply them promptly once available. 7. Consider temporary workarounds such as replacing or patching the vulnerable preProcess() functions to reject malformed input structures. 8. Educate development teams about prototype pollution risks and secure coding practices to prevent similar vulnerabilities in custom code.