CVE-2025-15412 is an out-of-bounds read vulnerability identified in the WebAssembly Binary Toolkit (wabt), specifically affecting the wasm-decompile component's function wabt::Decompiler::VarName. This vulnerability allows an attacker with local access and limited privileges to read memory outside the intended buffer boundaries, potentially exposing sensitive information or causing application instability. The flaw arises from improper bounds checking during the decompilation process of WebAssembly binaries. Since wabt is a widely used toolkit for WebAssembly binary analysis and manipulation, this vulnerability could impact developers and automated systems that rely on wasm-decompile for reverse engineering or debugging WebAssembly modules. Exploitation requires local access but no user interaction or elevated privileges beyond limited local rights, making it a low-complexity attack vector. The vulnerability has been publicly disclosed, but no official patch or fix is currently available due to the project's lack of an active maintainer. The community has suggested that researchers submit pull requests to address the issue. The CVSS v4.0 score is 4.8 (medium severity), reflecting the limited attack vector and impact scope. No known exploits have been reported in the wild, but the public disclosure increases the risk of future exploitation. This vulnerability primarily threatens confidentiality by enabling out-of-bounds reads, with potential secondary impacts on integrity or availability if exploited in complex attack chains. Organizations using wabt in development environments or automated pipelines should be aware of this risk and take appropriate precautions.

For European organizations, the primary impact of CVE-2025-15412 lies in the potential exposure of sensitive information through out-of-bounds memory reads when using the wabt toolkit for WebAssembly analysis or development. This could lead to leakage of proprietary code, cryptographic keys, or other confidential data embedded in WebAssembly binaries. Since exploitation requires local access, the threat is most relevant in environments where multiple users share development or build systems, or where attackers have gained limited footholds on developer machines or CI/CD infrastructure. The lack of an active maintainer and absence of official patches increases the risk that attackers could develop exploits, especially after public disclosure. This vulnerability could also disrupt development workflows if exploited to cause crashes or data corruption. Given the growing adoption of WebAssembly in European tech sectors, particularly in software development, fintech, and embedded systems, the vulnerability could affect organizations relying on wabt for debugging, reverse engineering, or security analysis. However, the limited attack vector and medium severity reduce the likelihood of widespread operational impact. Nonetheless, confidentiality breaches in sensitive development environments could have downstream effects on product security and intellectual property protection.

European organizations should implement strict access controls to limit local access to systems running wabt, especially those used for WebAssembly development or analysis. Employing role-based access control (RBAC) and ensuring that only trusted users can execute wasm-decompile reduces the attack surface. Monitoring and auditing usage of wabt binaries can help detect anomalous activity indicative of exploitation attempts. Since no official patch is available, organizations with in-house development expertise should consider reviewing the wabt source code to develop and apply custom patches addressing the out-of-bounds read. Contributing fixes back to the community can help restore project maintenance. Additionally, isolating build and analysis environments using containerization or virtual machines can contain potential exploitation impacts. Regularly updating related tooling and dependencies is advisable once patches become available. Finally, educating developers and system administrators about the risks of local vulnerabilities and enforcing least privilege principles will further reduce exposure.