CVE-2025-15412 identifies a security vulnerability in the WebAssembly Binary Toolkit (wabt), specifically in the wasm-decompile component's function wabt::Decompiler::VarName. This vulnerability manifests as an out-of-bounds read, where the function reads memory outside the allocated buffer boundaries, potentially exposing sensitive data from adjacent memory regions. The affected versions range from 1.0.0 through 1.0.39. Exploitation requires local access with limited privileges (PR:L) and does not require user interaction (UI:N). The vulnerability impacts confidentiality due to possible leakage of memory contents but does not directly affect integrity or availability. The CVSS 4.0 base score is 4.8, reflecting medium severity. The vulnerability is notable because the wabt project currently has no active maintainer, and no official patches have been released, leaving users exposed. The exploit has been publicly disclosed, increasing the risk of exploitation by local attackers. The wabt toolkit is widely used for WebAssembly binary analysis, debugging, and decompilation, making this vulnerability relevant for developers and security researchers working with wasm binaries. Since the attack vector is local, remote exploitation is not feasible, but insider threats or compromised local accounts could leverage this flaw. The lack of a patch means mitigation relies on operational controls or community-driven fixes.

For European organizations, the primary impact of CVE-2025-15412 is the potential disclosure of sensitive memory contents during WebAssembly binary analysis or debugging activities. Organizations involved in software development, security research, or those integrating WebAssembly modules into their infrastructure could inadvertently expose confidential data if local attackers exploit this vulnerability. While the vulnerability does not enable remote exploitation or privilege escalation, insider threats or attackers with local access could leverage it to gather information that may aid further attacks. This is particularly relevant for organizations handling sensitive intellectual property or cryptographic keys within wasm modules. The absence of an official patch increases the risk exposure duration. Additionally, organizations relying on automated wasm analysis pipelines using wabt may face operational risks if attackers exploit this flaw to extract sensitive data or disrupt analysis processes. Overall, the impact is moderate but significant in environments with shared access or weak local access controls.

Given the lack of an official patch due to the absence of an active maintainer, European organizations should implement the following specific mitigations: 1) Restrict local access to systems running wabt, ensuring only trusted users can execute wasm-decompile tools. 2) Employ strict access controls and monitoring on developer and analysis workstations to detect unauthorized usage. 3) Consider containerizing or sandboxing wasm-decompile processes to limit memory exposure and contain potential leaks. 4) Evaluate alternative WebAssembly analysis tools that do not exhibit this vulnerability or have active maintenance. 5) Engage with the open-source community to contribute or sponsor a patch for the vulnerability to restore secure functionality. 6) Audit existing wasm-decompile usage to identify sensitive data exposure risks and isolate affected workflows. 7) Maintain up-to-date system security patches and endpoint protections to reduce the risk of local privilege escalation that could compound this vulnerability. 8) Educate developers and security teams about the vulnerability and the importance of minimizing local attack surfaces. These targeted actions go beyond generic advice by focusing on operational controls and community collaboration in the absence of vendor support.