CVE-2025-39698

MEDIUM
2025-09-05 416baaa9-dc9f-4396-8d5f-8c081fb06d67
5.5
CVSS 3.1
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CVSS Vector

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Attack Vector
Local
Attack Complexity
Low
Privileges Required
Low
User Interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High

Lifecycle Timeline

3
Analysis Generated
Mar 28, 2026 - 19:10 vuln.today
Patch Released
Mar 28, 2026 - 19:10 nvd
Patch available
CVE Published
Sep 05, 2025 - 18:15 nvd
MEDIUM 5.5

Description

In the Linux kernel, the following vulnerability has been resolved: io_uring/futex: ensure io_futex_wait() cleans up properly on failure The io_futex_data is allocated upfront and assigned to the io_kiocb async_data field, but the request isn't marked with REQ_F_ASYNC_DATA at that point. Those two should always go together, as the flag tells io_uring whether the field is valid or not. Additionally, on failure cleanup, the futex handler frees the data but does not clear ->async_data. Clear the data and the flag in the error path as well. Thanks to Trend Micro Zero Day Initiative and particularly ReDress for reporting this.

Analysis

In the Linux kernel, the following vulnerability has been resolved: io_uring/futex: ensure io_futex_wait() cleans up properly on failure The io_futex_data is allocated upfront and assigned to the. Rated medium severity (CVSS 5.5), this vulnerability is low attack complexity. This Use After Free vulnerability could allow attackers to access freed memory to execute arbitrary code or crash the application.

Technical Context

This vulnerability is classified as Use After Free (CWE-416), which allows attackers to access freed memory to execute arbitrary code or crash the application. In the Linux kernel, the following vulnerability has been resolved: io_uring/futex: ensure io_futex_wait() cleans up properly on failure The io_futex_data is allocated upfront and assigned to the io_kiocb async_data field, but the request isn't marked with REQ_F_ASYNC_DATA at that point. Those two should always go together, as the flag tells io_uring whether the field is valid or not. Additionally, on failure cleanup, the futex handler frees the data but does not clear ->async_data. Clear the data and the flag in the error path as well. Thanks to Trend Micro Zero Day Initiative and particularly ReDress for reporting this. Affected products include: Linux Linux Kernel.

Affected Products

Linux Linux Kernel.

Remediation

A vendor patch is available. Apply the latest security update as soon as possible. Use smart pointers or garbage-collected languages. Set pointers to NULL after freeing. Enable memory sanitizers.

Priority Score

28
Low Medium High Critical
KEV: 0
EPSS: +0.0
CVSS: +28
POC: 0

Vendor Status

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CVE-2025-39698 vulnerability details – vuln.today

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