CVE-2026-115386
Description
A flaw was found in Wasmtime. An information disclosure vulnerability exists in the WebAssembly System Interface (WASI) directory reading implementation, which copies uninitialized structure padding into guest memory. A guest module with access to a preopened directory can exploit this issue by listing directory entries to read residual host stack or heap memory.
Statement
This vulnerability is rated as having a Low impact because the information disclosure is constrained to a minimal amount of residual host memory and requires specific host-granted access rights. Exploitation necessitates executing a WebAssembly guest module that has been explicitly provisioned with access to preopened directories. Because only three bytes of uninitialized structure padding are disclosed per directory entry, the potential exposure of sensitive host data is very limited and does not compromise system integrity or service availability.
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 | 3.3 | N/A | 2.6 |
| Attack Vector | Local | N/A | Network |
| Attack Complexity | Low | N/A | High |
| Privileges Required | Low | N/A | Low |
| User Interaction | None | N/A | Required |
| Scope | Unchanged | N/A | Unchanged |
| Confidentiality | Low | N/A | Low |
| Integrity Impact | None | N/A | None |
| Availability Impact | None | N/A | None |
Vector
Red Hat: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N
cve.org: CVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:U/C:L/I:N/A:N
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