CVE-2026-33150
Description
A flaw was found in libfuse. A use-after-free vulnerability in the io_uring subsystem allows a local attacker to potentially execute arbitrary code and crash FUSE (Filesystem in Userspace) filesystem processes. This occurs when io_uring thread creation fails due to resource exhaustion, such as limits imposed by cgroup pids.max, causing a dangling pointer to be stored and later used during session shutdown. This vulnerability is reliably triggered in containerized environments.
Statement
An Important use-after-free vulnerability in libfuse's io_uring subsystem can lead to arbitrary code execution or denial of service for local attackers. This flaw is reliably triggered in containerized environments when io_uring thread creation fails due to resource exhaustion, such as cgroup pids.max limits. Red Hat Enterprise Linux 7 is not affected. Red Hat Enterprise Linux 8.10 and Fedora are affected when using fuse-sshfs.
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 | 7.8 | N/A | 7.8 |
| 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 | Unchanged | N/A | Unchanged |
| Confidentiality | High | N/A | High |
| Integrity Impact | High | N/A | High |
| Availability Impact | High | N/A | High |
Vector
Red Hat: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
cve.org: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Understanding the Weakness (CWE)
Confidentiality
Technical Impact: Read Memory
If the expired pointer is used in a read operation, an attacker might be able to control data read in by the application.
Availability
Technical Impact: DoS: Crash, Exit, or Restart
If the expired pointer references a memory location that is not accessible to the product, or points to a location that is "malformed" (such as NULL) or larger than expected by a read or write operation, then a crash may occur.
Integrity,Confidentiality,Availability
Technical Impact: Execute Unauthorized Code or Commands
If the expired pointer is used in a function call, or points to unexpected data in a write operation, then code execution may be possible.
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