CVE-2026-118384
Description
A flaw was found in mtools. This out-of-bounds write vulnerability allows an attacker to cause a Denial of Service (DoS) or corrupt memory. By tricking a user into processing a specially crafted disk image containing malformed VFAT directory entries, the application writes beyond allocated buffer boundaries, resulting in an application crash.
Statement
This vulnerability is rated as Moderate for Red Hat Enterprise Linux because exploitation requires a user to explicitly inspect or manipulate an untrusted filesystem image using command-line utilities. In typical enterprise environments, mtools is not exposed as a continuously running network service or automated processing daemon, which confines any potential disruption strictly to the local context and execution lifecycle of the tool. Consequently, memory corruption leading to an unexpected process termination poses limited operational risk to the broader host system.
Mitigation
No fix is currently shipped. Mitigation: do not run mtools utilities (mdir/mcopy/etc.) against untrusted or attacker-supplied disk images; only process filesystem images from trusted sources. The flaw requires explicit local processing of a crafted VFAT image and is not remotely exploitable.
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 | 6.1 | N/A | 6.1 |
| Attack Vector | Local | N/A | Local |
| Attack Complexity | Low | N/A | Low |
| Privileges Required | None | N/A | None |
| User Interaction | Required | N/A | Required |
| Scope | Unchanged | N/A | Unchanged |
| Confidentiality | None | N/A | None |
| Integrity Impact | Low | N/A | Low |
| Availability Impact | High | N/A | High |
Vector
Red Hat: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:H
cve.org: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:H
Understanding the Weakness (CWE)
Integrity
Technical Impact: Modify Memory; Execute Unauthorized Code or Commands
Write operations could cause memory corruption. In some cases, an adversary can modify control data such as return addresses in order to execute unexpected code.
Availability
Technical Impact: DoS: Crash, Exit, or Restart
Attempting to access out-of-range, invalid, or unauthorized memory could cause the product to crash.
Other
Technical Impact: Unexpected State
Subsequent write operations can produce undefined or unexpected results.
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