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Fencer Vulns
medium 5.3

CVE-2019-20934 json

An issue was discovered in the Linux kernel before 5.2.6.

published 2020-11-28 5 y ago modified 2026-06-17 4 mo ago also EUVD-2019-11463

cvss
5.3
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
0.3%
EPSS 0.3% chance of exploitation in 30 days, percentile 24%
public exploits
0
none known

Summary

An issue was discovered in the Linux kernel before 5.2.6. On NUMA systems, the Linux fair scheduler has a use-after-free in show_numa_stats() because NUMA fault statistics are inappropriately freed, aka CID-16d51a590a8c.

Patch / fix

  • linux linux_kernel 4.19.64
  • linux Debian 14, Debian 13, Debian 12 5.2.6-1

debian advisories DEBIAN-CVE-2019-20934

  • linux Ubuntu 16.04 LTS 4.4.0-165.193
  • linux Ubuntu 18.04 LTS 4.15.0-60.67
  • linux-aws Ubuntu 16.04 LTS 4.4.0-1095.106
  • linux-aws Ubuntu 18.04 LTS 4.15.0-1047.49
  • linux-gcp Ubuntu 16.04 LTS 4.15.0-1041.43
  • linux-hwe Ubuntu 16.04 LTS 4.15.0-60.67~16.04.1
  • linux-kvm Ubuntu 16.04 LTS 4.4.0-1059.66
  • linux-kvm Ubuntu 18.04 LTS 4.15.0-1043.43

ubuntu advisories UBUNTU-CVE-2019-20934

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 3.10.0-1160.36.2.el7
  • perf RHEL 7 3.10.0-1160.36.2.el7
  • bpftool RHEL 7 3.10.0-1160.36.2.el7
  • python-perf RHEL 7 3.10.0-1160.36.2.el7
  • kernel-kdump RHEL 7 3.10.0-1160.36.2.el7
  • kernel-tools RHEL 7 3.10.0-1160.36.2.el7
  • kernel-tools-libs RHEL 7 3.10.0-1160.36.2.el7
  • kernel-bootwrapper RHEL 7 3.10.0-1160.36.2.el7

red hat advisories RHSA-2021:3987RHSA-2021:2725RHSA-2021:2726

  • kernel-syms SLES for SAP 12 SP3, SLES 12 SP3-LTSS, SLES 12 SP3-BCL +4 more 4.4.180-94.138.1
  • kernel-source SLES for SAP 12 SP3, SLES 12 SP3-LTSS, SLES 12 SP3-BCL +4 more 4.4.180-94.138.1
  • kernel-default SLES for SAP 12 SP3, SLES 12 SP3-LTSS, SLES 12 SP3-BCL +5 more 4.4.180-94.138.1
  • kgraft-patch-SLE12-SP3_Update_37 SLES for SAP 12 SP3, SLES 12 SP3-LTSS, OpenStack Cloud Crowbar 8 +3 more 1-4.3.1
  • kernel-syms SLES for SAP 15, SLES 15-LTSS, SLE High Performance Computing 15-LTSS +1 more 4.12.14-150.66.1
  • kernel-source SLES for SAP 15, SLES 15-LTSS, SLE High Performance Computing 15-LTSS +1 more 4.12.14-150.66.1
  • kernel-default SLES for SAP 15, SLES 15-LTSS, SLE Live Patching 15 +3 more 4.12.14-150.66.1
  • kernel-vanilla SLES for SAP 15, SLES 15-LTSS, SLE High Performance Computing 15-LTSS +1 more 4.12.14-150.66.1

suse advisories SUSE-SU-2021:0452-1SUSE-SU-2021:0438-1SUSE-SU-2021:0437-1SUSE-SU-2021:0434-1SUSE-SU-2021:0133-1SUSE-SU-2021:0118-1

  • kernel-syms openSUSE Leap 15.1 4.12.14-lp151.28.91.1
  • kernel-obs-qa openSUSE Leap 15.1 4.12.14-lp151.28.91.1
  • kernel-source openSUSE Leap 15.1 4.12.14-lp151.28.91.1
  • kernel-default openSUSE Leap 15.1 4.12.14-lp151.28.91.1
  • kernel-vanilla openSUSE Leap 15.1 4.12.14-lp151.28.91.1
  • kernel-kvmsmall openSUSE Leap 15.1 4.12.14-lp151.28.91.1
  • kernel-obs-build openSUSE Leap 15.1 4.12.14-lp151.28.91.1

opensuse advisories openSUSE-SU-2021:0075-1

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-2019-20934 updated cvss 5.3

kernel: use-after-free in show_numa_stats function

  • Red Hat Enterprise Linux 5 kernel Red Hat Enterprise Linux 6 perf, kernel, python-perf, kernel-kdump, kernel-firmware, kernel-bootwrapper, +1 more
    affected: workaround, no fix planned “Out of support scope”
  • Red Hat Enterprise Linux 7 perf, kernel, kernel-alt, python-perf, kernel-kdump, kernel-tools, +3 more
    affected: workaround, no fix planned “Will not fix”
  • Red Hat Enterprise Linux Client (v. 7) perf 3.10.0-1160.36.2.el7, kernel 3.10.0-1160.36.2.el7, bpftool 3.10.0-1160.36.2.el7, python-perf 3.10.0-1160.36.2.el7, kernel-tools 3.10.0-1160.36.2.el7, kernel-tools-libs 3.10.0-1160.36.2.el7, +2 more Red Hat Enterprise Linux Client Optional (v. 7) kernel-debuginfo-common-x86_64 3.10.0-1160.36.2.el7 Red Hat Enterprise Linux ComputeNode Optional (v. 7) kernel-debuginfo-common-x86_64 3.10.0-1160.36.2.el7
    fixed: vendor fix RHSA-2021:2725
  • Red Hat Enterprise Linux for Real Time (v. 7) kernel-rt 3.10.0-1160.36.2.rt56.1179.el7, kernel-rt-trace 3.10.0-1160.36.2.rt56.1179.el7, kernel-rt-debuginfo-common-x86_64 3.10.0-1160.36.2.rt56.1179.el7 Red Hat Enterprise Linux for Real Time for NFV (v. 7) kernel-rt 3.10.0-1160.36.2.rt56.1179.el7, kernel-rt-kvm 3.10.0-1160.36.2.rt56.1179.el7, kernel-rt-trace 3.10.0-1160.36.2.rt56.1179.el7, kernel-rt-debug-kvm 3.10.0-1160.36.2.rt56.1179.el7, kernel-rt-trace-kvm 3.10.0-1160.36.2.rt56.1179.el7, kernel-rt-debuginfo-common-x86_64 3.10.0-1160.36.2.rt56.1179.el7
    fixed: vendor fix RHSA-2021:2726
  • Red Hat Enterprise Linux Server (v. 7) perf 3.10.0-1160.36.2.el7, kernel 3.10.0-1160.36.2.el7, bpftool 3.10.0-1160.36.2.el7, python-perf 3.10.0-1160.36.2.el7, kernel-kdump 3.10.0-1160.36.2.el7, kernel-tools 3.10.0-1160.36.2.el7, +7 more
    fixed: vendor fix RHSA-2021:2725
  • Red Hat Enterprise Linux Server AUS (v. 7.7) perf 3.10.0-1062.59.1.el7, kernel 3.10.0-1062.59.1.el7, bpftool 3.10.0-1062.59.1.el7, python-perf 3.10.0-1062.59.1.el7, kernel-tools 3.10.0-1062.59.1.el7, kernel-tools-libs 3.10.0-1062.59.1.el7, +2 more Red Hat Enterprise Linux Server E4S (v. 7.7) perf 3.10.0-1062.59.1.el7, kernel 3.10.0-1062.59.1.el7, bpftool 3.10.0-1062.59.1.el7, python-perf 3.10.0-1062.59.1.el7, kernel-tools 3.10.0-1062.59.1.el7, kernel-tools-libs 3.10.0-1062.59.1.el7, +4 more
    fixed: vendor fix RHSA-2021:3987
  • Red Hat Enterprise Linux Server Optional (v. 7) kernel-debuginfo-common-ppc64 3.10.0-1160.36.2.el7, kernel-debuginfo-common-x86_64 3.10.0-1160.36.2.el7, kernel-debuginfo-common-ppc64le 3.10.0-1160.36.2.el7
    fixed: vendor fix RHSA-2021:2725
  • Red Hat Enterprise Linux Server Optional AUS (v. 7.7) kernel-debuginfo-common-x86_64 3.10.0-1062.59.1.el7 Red Hat Enterprise Linux Server Optional E4S (v. 7.7) kernel-debuginfo-common-x86_64 3.10.0-1062.59.1.el7, kernel-debuginfo-common-ppc64le 3.10.0-1062.59.1.el7 Red Hat Enterprise Linux Server Optional TUS (v. 7.7) kernel-debuginfo-common-x86_64 3.10.0-1062.59.1.el7 Red Hat Enterprise Linux Server TUS (v. 7.7) perf 3.10.0-1062.59.1.el7, kernel 3.10.0-1062.59.1.el7, bpftool 3.10.0-1062.59.1.el7, python-perf 3.10.0-1062.59.1.el7, kernel-tools 3.10.0-1062.59.1.el7, kernel-tools-libs 3.10.0-1062.59.1.el7, +2 more
    fixed: vendor fix RHSA-2021:3987
show 2 more
  • Red Hat Enterprise Linux Workstation (v. 7) perf 3.10.0-1160.36.2.el7, kernel 3.10.0-1160.36.2.el7, bpftool 3.10.0-1160.36.2.el7, python-perf 3.10.0-1160.36.2.el7, kernel-tools 3.10.0-1160.36.2.el7, kernel-tools-libs 3.10.0-1160.36.2.el7, +2 more Red Hat Enterprise Linux Workstation Optional (v. 7) kernel-debuginfo-common-x86_64 3.10.0-1160.36.2.el7
    fixed: vendor fix RHSA-2021:2725
  • Red Hat Enterprise Linux 8 perf, kernel, bpftool, kernel-rt, kernel-core, kernel-tools, +29 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

0.32% chance of exploitation in the next 30 days, higher than 24% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
NVD 3.1 5.3 CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:L/I:N/A:H
NVD 2.0 5.4 AV:L/AC:M/Au:N/C:P/I:N/A:C

Classification

Weakness
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.