CVE-2025-62711 is a vulnerability identified in the Wasmtime WebAssembly runtime, specifically affecting versions from 38.0.0 up to but not including 38.0.3. The issue stems from improper handling of exceptional conditions within the component-model related host-to-wasm trampolines. These trampolines facilitate calls between host environments and WebAssembly modules. A carefully crafted WebAssembly component can exploit this flaw by triggering a specific call sequence that causes the host process running Wasmtime to crash, either through a segmentation fault or an assertion failure. This vulnerability is classified under CWE-755, which relates to improper handling of exceptional conditions. The crash impacts the availability of the host application or service relying on Wasmtime, potentially leading to denial of service. The CVSS 4.0 vector indicates network attack vector (AV:N), high attack complexity (AC:H), partial privileges required (PR:L), partial user interaction (UI:P), and low impact on availability (VA:L) with no impact on confidentiality or integrity. No known exploits are currently in the wild, and no workarounds exist other than applying the patch. The vendor has addressed the issue in Wasmtime version 38.0.3, which corrects the trampoline implementation to prevent such crashes. This vulnerability primarily affects environments embedding Wasmtime for running WebAssembly components, including cloud services, development tools, and edge computing platforms.

For European organizations, the primary impact of CVE-2025-62711 is a potential denial-of-service condition caused by host crashes when processing malicious WebAssembly components. This can disrupt services or development workflows that rely on Wasmtime, particularly in environments where WebAssembly is used for sandboxing or extending application functionality. While the vulnerability does not compromise data confidentiality or integrity, availability interruptions can affect business continuity, especially for cloud providers, SaaS platforms, and enterprises leveraging WebAssembly for modular application design. Organizations with automated pipelines or edge computing deployments using Wasmtime may experience service degradation or outages if targeted. The low CVSS score reflects the limited scope and complexity of exploitation, but the risk is non-negligible in critical infrastructure or high-availability systems. European entities in sectors such as finance, telecommunications, and technology that integrate Wasmtime into their software stacks should prioritize patching to avoid operational disruptions.

The definitive mitigation for CVE-2025-62711 is to upgrade all affected Wasmtime instances to version 38.0.3 or later, where the vulnerability has been fixed. Organizations should implement a thorough inventory of systems and development environments using Wasmtime to ensure no outdated versions remain in production or testing. Additionally, auditing WebAssembly components for unexpected or malformed inputs can help detect attempts to exploit this vulnerability. Incorporating runtime monitoring and alerting for abnormal crashes or assertion failures in Wasmtime hosts can provide early warning of exploitation attempts. For environments where immediate patching is not feasible, isolating Wasmtime processes and limiting their privileges can reduce potential impact. Finally, integrating Wasmtime updates into continuous integration/continuous deployment (CI/CD) pipelines will help maintain secure versions going forward.