CVE-2009-4141

What it is

Use-after-free vulnerability in the fasync_helper function in fs/fcntl.c in the Linux kernel before 2.6.33-rc4-git1 allows local users to gain privileges via vectors that include enabling O_ASYNC (aka FASYNC or FIOASYNC) on a locked file, and then closing this file.

At a glance

Exploitability

Can be exploited locally on the machine without logging in. High risk of data exposure, data tampering, service disruption.

Exploit odds

1.0% chance of exploitation in the next 30 days (EPSS).

Fix

A patch, advisory or fixed version is referenced. Upgrade or apply it.

Timeline

1. 2010-01-19 16:30 UTC PublishedDisclosed publicly on CVE.org and NVD
2. 2026-06-16 23:13 UTC Last updatedMost recent change to the record

Why it ranks here

• Exploited in the wild: no, CISA does not list it.
• Exploit odds: 1.0% in the next 30 days (EPSS).
• Severity: 7.2 HIGH (CVSS).
• Fix: a patch or advisory is linked.

Details

Published

2010-01-19 16:30 UTC

Last modified

2026-06-16 23:13 UTC

Exploit probability

1.0% · EPSS, next 30 days

Weakness

CWE-399

Record status

Modified

Affected

• Linux Kernel ≤ 2.6.33
• Linux Kernel 2.6.0
• Linux Kernel 2.6.1
• Linux Kernel 2.6.2
• Linux Kernel 2.6.3
• Linux Kernel 2.6.4
• Linux Kernel 2.6.5
• Linux Kernel 2.6.6

Attack profile CVSS 2.0 · 7.2

Attack vector

Local

Complexity

Low

Authentication

None

Confidentiality

Complete

Integrity

Complete

Availability

Complete

Is it in your code?

Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.

Read https://cve-list.com/agent/cve/CVE-2009-4141.md and follow it. Check whether this project is affected by CVE-2009-4141. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.

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