CVE-2026-58494
Description
A flaw was found in Wasmtime, a runtime for WebAssembly. A WebAssembly System Interface (WASI) guest with a read-only source file capability can exploit this vulnerability. During hard-link creation and renaming operations, the system checks directory permissions but fails to match file permissions on source and destination preopens. This allows the guest to overwrite host files exposed with read permissions through WASI filesystem interfaces.
Statement
This Moderate-impact flaw in Wasmtime allows a malicious WebAssembly System Interface (WASI) guest to overwrite host files. By exploiting insufficient permission checks during hard-link and rename operations, a guest with read-only file capabilities can modify host files that are exposed with read permissions through WASI filesystem interfaces. This could lead to data integrity issues on the host system.
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 | 6.5 | N/A | 6.5 |
| Attack Vector | Local | N/A | Local |
| Attack Complexity | Low | N/A | Low |
| Privileges Required | Low | N/A | Low |
| User Interaction | None | N/A | None |
| Scope | Changed | N/A | Changed |
| Confidentiality | None | N/A | None |
| Integrity Impact | High | N/A | High |
| Availability Impact | None | N/A | None |
Vector
Red Hat: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:N/I:H/A:N
cve.org: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:N/I:H/A:N
Understanding the Weakness (CWE)
Other
Technical Impact: Other; Alter Execution Logic
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