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Fencer Vulns
high 8.1

CVE-2017-15126 json

A use-after-free flaw was found in fs/userfaultfd.c in the Linux kernel before 4.13.6.

published 2018-01-14 8 y ago modified 2026-06-17 4 mo ago also EUVD-2017-6587

cvss
8.1
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
4.1%
EPSS 4.1% chance of exploitation in 30 days, percentile 90%
public exploits
0
none known

Summary

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().

Patch / fix

  • linux linux_kernel 4.13.6
  • linux Debian 14, Debian 13, Debian 12 4.13.10-1

debian advisories DEBIAN-CVE-2017-15126

  • linux-azure Ubuntu 16.04 LTS 4.13.0-1005.7

ubuntu advisories UBUNTU-CVE-2017-15126

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • kernel RHEL 7 3.10.0-862.el7
  • perf RHEL 7 3.10.0-862.el7
  • python-perf RHEL 7 3.10.0-862.el7
  • kernel-kdump RHEL 7 3.10.0-862.el7
  • kernel-tools RHEL 7 3.10.0-862.el7
  • kernel-tools-libs RHEL 7 3.10.0-862.el7
  • kernel-bootwrapper RHEL 7 3.10.0-862.el7
  • kernel-abi-whitelists RHEL 7 3.10.0-862.el7

red hat advisories RHSA-2018:1062RHSA-2018:0676

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2017-15126 updated cvss 7.0

kernel: Use-after-free in userfaultfd_event_wait_completion function in userfaultfd.c

  • Red Hat Enterprise MRG 2 kernel-rt, mrg-rt-release, kernel-rt-trace, kernel-rt-vanilla, kernel-rt-firmware
    affected: no fix available
  • Red Hat Enterprise Linux Client (v. 7) perf 3.10.0-862.el7, kernel 3.10.0-862.el7, python-perf 3.10.0-862.el7, kernel-tools 3.10.0-862.el7, kernel-tools-libs 3.10.0-862.el7, kernel-abi-whitelists 3.10.0-862.el7, +1 more Red Hat Enterprise Linux Client Optional (v. 7) kernel-debuginfo-common-x86_64 3.10.0-862.el7 Red Hat Enterprise Linux ComputeNode (v. 7) perf 3.10.0-862.el7, kernel 3.10.0-862.el7, python-perf 3.10.0-862.el7, kernel-tools 3.10.0-862.el7, kernel-tools-libs 3.10.0-862.el7, kernel-abi-whitelists 3.10.0-862.el7, +1 more Red Hat Enterprise Linux ComputeNode Optional (v. 7) kernel-debuginfo-common-x86_64 3.10.0-862.el7
    fixed: vendor fix RHSA-2018:1062
  • Red Hat Enterprise Linux for Real Time (v. 7) kernel-rt 3.10.0-862.rt56.804.el7, kernel-rt-trace 3.10.0-862.rt56.804.el7, kernel-rt-debuginfo-common-x86_64 3.10.0-862.rt56.804.el7 Red Hat Enterprise Linux for Real Time for NFV (v. 7) kernel-rt 3.10.0-862.rt56.804.el7, kernel-rt-kvm 3.10.0-862.rt56.804.el7, kernel-rt-trace 3.10.0-862.rt56.804.el7, kernel-rt-debug-kvm 3.10.0-862.rt56.804.el7, kernel-rt-trace-kvm 3.10.0-862.rt56.804.el7, kernel-rt-debuginfo-common-x86_64 3.10.0-862.rt56.804.el7
    fixed: vendor fix RHSA-2018:0676
  • Red Hat Enterprise Linux Server (v. 7) perf 3.10.0-862.el7, kernel 3.10.0-862.el7, python-perf 3.10.0-862.el7, kernel-kdump 3.10.0-862.el7, kernel-tools 3.10.0-862.el7, kernel-tools-libs 3.10.0-862.el7, +6 more Red Hat Enterprise Linux Server Optional (v. 7) kernel-debuginfo-common-ppc64 3.10.0-862.el7, kernel-debuginfo-common-x86_64 3.10.0-862.el7, kernel-debuginfo-common-ppc64le 3.10.0-862.el7 Red Hat Enterprise Linux Workstation (v. 7) perf 3.10.0-862.el7, kernel 3.10.0-862.el7, python-perf 3.10.0-862.el7, kernel-tools 3.10.0-862.el7, kernel-tools-libs 3.10.0-862.el7, kernel-abi-whitelists 3.10.0-862.el7, +1 more Red Hat Enterprise Linux Workstation Optional (v. 7) kernel-debuginfo-common-x86_64 3.10.0-862.el7
    fixed: vendor fix RHSA-2018:1062
  • Red Hat Enterprise Linux 5 kernel Red Hat Enterprise Linux 6 perf, kernel, python-perf, kernel-kdump, kernel-firmware, kernel-bootwrapper, +1 more Red Hat Enterprise Linux 7 perf, kernel, kernel-alt, python-perf, kernel-kdump, kernel-tools, +3 more Red Hat Enterprise Linux 8 perf, kernel, bpftool, kernel-core, kernel-tools, python3-perf, +17 more
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

Exploit prediction

4.08% chance of exploitation in the next 30 days, higher than 90% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
NVD 3.1 8.1 CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
NVD 2.0 9.3 AV:N/AC:M/Au:N/C:C/I:C/A:C

Affected products

  • n/a Linux Kernel before 4.13.6

Classification

Weakness
  • CWE-119 Improper Restriction of Operations within the Bounds of a Memory Buffer
  • CWE-416 Use After Free
Technology feeds

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.