CVE-2026-115389
Description
A flaw was found in Wasmtime. The runtime does not adequately account for host memory allocations when converting guest values through the dynamically-typed Val application programming interface (API), bypassing configured resource consumption limits. A malicious WebAssembly guest can exploit this vulnerability by returning crafted values that consume far more host memory than tracked. This uncontrolled memory allocation can exhaust system resources, resulting in a Denial of Service (DoS).
Statement
This vulnerability is rated as Low severity because exploitation results solely in a localized denial of service and requires an attacker to execute a crafted WebAssembly guest module within an embedding host application. In Red Hat environments, Wasmtime is utilized within specific runtime shims where the deployment of unvetted guest modules is strictly controlled. Furthermore, the issue only affects integrations that lift values using dynamically typed inspection interfaces rather than statically typed bindings, substantially reducing the practical attack surface under default configurations.
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 | 2.5 | N/A | 2.3 |
| Attack Vector | Local | N/A | Adjacent Network |
| Attack Complexity | High | N/A | High |
| Privileges Required | Low | N/A | Low |
| User Interaction | None | N/A | Required |
| Scope | Unchanged | N/A | Unchanged |
| Confidentiality | None | N/A | None |
| Integrity Impact | None | N/A | None |
| Availability Impact | Low | N/A | Low |
Vector
Red Hat: CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:L
cve.org: CVSS:3.1/AV:A/AC:H/PR:L/UI:R/S:U/C:N/I:N/A:L
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