CVE-2017-15126 Use after free in Linux Kernel before 4.13.6

What is CVE-2017-15126?

CVE-2017-15126 is a high-severity use after free vulnerability in Linux kernel, published on 14 Jan 2018. An attacker can exploit it over the internet without logging in, with no action from the victim.

Official description

A use-after-free flaw was found in fs/userfaultfd.c in the Linux kernel before 4.13.6. The issue is related to the handling of fork failure when dealing with event messages. Failure to fork correctly can lead to a situation where a fork event will be removed from an already freed list of events with userfaultfd_ctx_put().

Weakness: CWE-416, CWE-119

Which versions are affected by CVE-2017-15126?

It affects 1 product.

Products include Linux kernel.

How do I fix CVE-2017-15126?

Apply the vendor's patch.

Upgrade to the fixed version. These bugs are found with fuzzing and sanitisers and avoided by memory-safe languages. More about Use after free.

Is CVE-2017-15126 being exploited?

There is no known exploitation of CVE-2017-15126 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 DEBIAN-CVE-2017-15126, GHSA-v4mc-2f9f-5jw2, UBUNTU-CVE-2017-15126.