CVE-2009-4307 Denial of service in n/a

What is CVE-2009-4307?

CVE-2009-4307 is a high-severity denial of service vulnerability in Linux kernel, published on 13 Dec 2009. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link.

Official description

The ext4_fill_flex_info function in fs/ext4/super.c in the Linux kernel before 2.6.32-git6 allows user-assisted remote attackers to cause a denial of service (divide-by-zero error and panic) via a malformed ext4 filesystem containing a super block with a large FLEX_BG group size (aka s_log_groups_per_flex value).

Weakness: CWE-189

Which versions are affected by CVE-2009-4307?

It affects 1 product.

Products include Linux kernel.

How do I fix CVE-2009-4307?

Upgrade to a fixed version.

Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.

Is CVE-2009-4307 being exploited?

There is no known exploitation of CVE-2009-4307 in the wild and no public exploit code.

Other vulnerabilities in Linux kernel

• CVE-2026-53266 Linux Kernel Out-of-Bounds Write Exploited High 8.8
• CVE-2013-6282 Linux Kernel Improper Input Validation Exploited High 8.8
• CVE-2022-0185 Linux Kernel Heap-Based Buffer Overflow Exploited High 8.4
• CVE-2013-2094 Linux Kernel Privilege Escalation Exploited High 8.4
• CVE-2026-53362 Linux Kernel Unspecified Exploited High 7.8

All Linux kernel vulnerabilities

Sources

• CVE record
• NVD
• OSV
• GitHub advisory
• How this page is made

Also known as GHSA-w39x-wg96-vcgw.