CVE-2025-14957 is a vulnerability identified in WebAssembly Binaryen up to version 125, specifically within the IRBuilder component's functions makeLocalGet, makeLocalSet, and makeLocalTee located in src/wasm/wasm-ir-builder.cpp. The vulnerability arises from improper handling of the argument Index, which leads to a null pointer dereference. This type of flaw typically results in application crashes or denial of service conditions when the affected functions attempt to access or manipulate memory through a null pointer. The attack vector requires local access with low privileges, meaning an attacker must have some level of access to the system but does not require elevated privileges or user interaction. The vulnerability does not affect confidentiality or integrity directly but impacts availability by causing potential crashes. The exploit code is publicly available, increasing the risk of exploitation, although no known active exploitation campaigns have been reported. The vendor has released a patch identified by commit 6fb2b917a79578ab44cf3b900a6da4c27251e0d4 to address the issue. The CVSS 4.0 base score is 4.8, reflecting a medium severity due to the limited attack vector and impact scope. This vulnerability is relevant for organizations that use Binaryen in their WebAssembly toolchains or runtime environments, especially in development or CI/CD pipelines where local code execution is common.

For European organizations, the primary impact of CVE-2025-14957 is the potential for denial of service or application instability in environments utilizing WebAssembly Binaryen version 125. This can disrupt software development workflows, continuous integration systems, or production environments that rely on WebAssembly compilation or optimization. While the vulnerability does not directly compromise data confidentiality or integrity, service availability interruptions can lead to operational delays and increased remediation costs. Organizations with internal development teams or cloud environments running WebAssembly toolchains are at risk if local access controls are weak or if untrusted users have local system access. The presence of a public exploit increases the likelihood of opportunistic attacks, especially in shared or multi-tenant environments. European sectors with high reliance on software development, such as finance, telecommunications, and technology, may experience indirect impacts through disrupted development cycles or compromised build environments.

To mitigate CVE-2025-14957, European organizations should immediately apply the official patch identified by commit 6fb2b917a79578ab44cf3b900a6da4c27251e0d4 to all affected Binaryen installations. Additionally, enforce strict local access controls to limit who can execute or modify WebAssembly toolchains, reducing the risk of exploitation by unauthorized users. Implement monitoring and alerting for abnormal crashes or service disruptions related to WebAssembly compilation processes. In development and CI/CD environments, isolate build systems and restrict execution privileges to trusted users only. Regularly update WebAssembly-related dependencies and maintain an inventory of software versions to quickly identify vulnerable instances. Conduct security reviews of WebAssembly integration points and consider sandboxing or containerization to limit the blast radius of potential crashes. Finally, educate developers and system administrators about this vulnerability and the importance of applying patches promptly.