CVE-2026-115892
Description
A flaw was found in Wasmtime. A malicious WebAssembly guest can cause a Denial of Service (DoS) by triggering an unhandled host runtime panic. When handling asynchronous streams or futures exchanged between the host and guest, Wasmtime fails to properly validate payload data types upon their return. An untrusted guest can exploit this behavior by manipulating return values with mismatched types, causing the host application to terminate unexpectedly.
Statement
This vulnerability is rated as having Moderate severity for Red Hat products because triggering the flaw requires an attacker to supply a crafted WebAssembly guest module in an environment utilizing component-model asynchronous streaming, and successful exploitation only induces a host process panic leading to denial of service without compromising memory integrity or confidentiality. In typical Red Hat deployments incorporating Wasmtime, such as WebAssembly shims or embedding runtimes, services are only exposed if they pass host-generated type-erased streams or futures to untrusted guest code and consume the returned mismatched payloads. Environments that do not execute untrusted WebAssembly components or that rely strictly on concrete, statically typed stream interfaces are not vulnerable to this condition.
Common Vulnerability Scoring System (CVSS) Score Details
Info alert:Important note
CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authority (CNA) source for its products and services (see Red Hat classifications).
The following CVSS metrics and score provided are preliminary and subject to review.
CVSS v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 5.5 | N/A | N/A |
| Attack Vector | Local | N/A | N/A |
| Attack Complexity | Low | N/A | N/A |
| Privileges Required | Low | N/A | N/A |
| User Interaction | None | N/A | N/A |
| Scope | Unchanged | N/A | N/A |
| Confidentiality | None | N/A | N/A |
| Integrity Impact | None | N/A | N/A |
| Availability Impact | High | N/A | N/A |
Vector
Red Hat: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Frequently Asked Questions
Not sure what something means? Check out our Security Glossary.
Want to get errata notifications? Sign up here.
