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Fencer Vulns
medium 6.1

CVE-2020-8647 json

There is a use-after-free vulnerability in the Linux kernel through 5.5.2 in the vc_do_resize function in drivers/tty/vt/vt.c.

published 2020-02-06 6 y ago modified 2026-06-17 4 mo ago also EUVD-2020-29495

cvss
6.1
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
0.4%
EPSS 0.4% chance of exploitation in 30 days, percentile 34%
public exploits
0
none known

Summary

There is a use-after-free vulnerability in the Linux kernel through 5.5.2 in the vc_do_resize function in drivers/tty/vt/vt.c.

Patch / fix

  • linux Debian 14, Debian 13, Debian 12 5.5.13-1

debian advisories DEBIAN-CVE-2020-8647

  • linux Ubuntu 16.04 LTS 4.4.0-178.208
  • linux Ubuntu 18.04 LTS 4.15.0-99.100
  • linux-aws Ubuntu 16.04 LTS 4.4.0-1106.117
  • linux-aws Ubuntu 18.04 LTS 4.15.0-1066.70
  • linux-gcp Ubuntu 16.04 LTS 4.15.0-1061.65
  • linux-hwe Ubuntu 16.04 LTS 4.15.0-99.100~16.04.1
  • linux-hwe Ubuntu 18.04 LTS 5.3.0-51.44~18.04.2
  • linux-kvm Ubuntu 16.04 LTS 4.4.0-1070.77

ubuntu advisories UBUNTU-CVE-2020-8647

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 8 4.18.0-240.el8
  • perf RHEL 8 4.18.0-240.el8
  • bpftool RHEL 8 4.18.0-240.el8
  • kernel-core RHEL 8 4.18.0-240.el8
  • kernel-tools RHEL 8 4.18.0-240.el8
  • python3-perf RHEL 8 4.18.0-240.el8
  • kernel-modules RHEL 8 4.18.0-240.el8
  • kernel-zfcpdump RHEL 8 4.18.0-240.el8

red hat advisories RHSA-2020:4431RHSA-2020:4060RHSA-2022:1213RHSA-2022:1209RHSA-2020:4609RHSA-2020:4062

  • kernel-syms SLES for SAP 15, SLES 15-LTSS, SLE High Performance Computing 15-LTSS +1 more 4.12.14-150.52.1
  • kernel-source SLES for SAP 15, SLES 15-LTSS, SLE High Performance Computing 15-LTSS +1 more 4.12.14-150.52.1
  • kernel-default SLES for SAP 15, SLES 15-LTSS, SLE Live Patching 15 +3 more 4.12.14-150.52.1
  • kernel-vanilla SLES for SAP 15, SLES 15-LTSS, SLE High Performance Computing 15-LTSS +1 more 4.12.14-150.52.1
  • kernel-obs-build SLES for SAP 15, SLES 15-LTSS, SLE High Performance Computing 15-LTSS +1 more 4.12.14-150.52.1
  • kernel-syms SLES for SAP 12 SP2, SLES 12 SP2-LTSS, SLES 12 SP2-BCL +1 more 4.4.121-92.129.1
  • kernel-source SLES for SAP 12 SP2, SLES 12 SP2-LTSS, SLES 12 SP2-BCL +1 more 4.4.121-92.129.1
  • kernel-default SLES for SAP 12 SP2, SLES 12 SP2-LTSS, SLES 12 SP2-BCL +2 more 4.4.121-92.129.1

suse advisories SUSE-SU-2020:1663-1SUSE-SU-2020:1255-1SUSE-SU-2020:1275-1SUSE-SU-2020:14354-1SUSE-SU-2020:1142-1SUSE-SU-2020:1141-1

  • kernel-syms openSUSE Leap 15.1 4.12.14-lp151.28.44.1
  • kernel-obs-qa openSUSE Leap 15.1 4.12.14-lp151.28.44.1
  • kernel-source openSUSE Leap 15.1 4.12.14-lp151.28.44.1
  • kernel-default openSUSE Leap 15.1 4.12.14-lp151.28.44.1
  • kernel-vanilla openSUSE Leap 15.1 4.12.14-lp151.28.44.1
  • kernel-kvmsmall openSUSE Leap 15.1 4.12.14-lp151.28.44.1
  • kernel-obs-build openSUSE Leap 15.1 4.12.14-lp151.28.44.1

opensuse advisories openSUSE-SU-2020:0388-1

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-2020-8647 updated cvss 6.1

kernel: out-of-bounds read in in vc_do_resize function in drivers/tty/vt/vt.c

  • 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 available
  • Red Hat Enterprise MRG 2 kernel
    affected: workaround, no fix planned “Will not fix”
  • Red Hat CodeReady Linux Builder (v. 8) kernel-debuginfo-common-x86_64 4.18.0-240.el8, kernel-debuginfo-common-aarch64 4.18.0-240.el8, kernel-debuginfo-common-ppc64le 4.18.0-240.el8
    fixed: vendor fix RHSA-2020:4431
  • Red Hat CodeReady Linux Builder EUS (v. 8.2) kernel-debuginfo-common-x86_64 4.18.0-193.80.1.el8_2, kernel-debuginfo-common-aarch64 4.18.0-193.80.1.el8_2, kernel-debuginfo-common-ppc64le 4.18.0-193.80.1.el8_2
    fixed: vendor fix RHSA-2022:1213
  • Red Hat Enterprise Linux BaseOS (v. 8) perf 4.18.0-240.el8, kernel 4.18.0-240.el8, bpftool 4.18.0-240.el8, kernel-core 4.18.0-240.el8, kernel-tools 4.18.0-240.el8, python3-perf 4.18.0-240.el8, +15 more
    fixed: vendor fix RHSA-2020:4431
  • Red Hat Enterprise Linux BaseOS EUS (v. 8.2) perf 4.18.0-193.80.1.el8_2, kernel 4.18.0-193.80.1.el8_2, bpftool 4.18.0-193.80.1.el8_2, kernel-core 4.18.0-193.80.1.el8_2, kernel-tools 4.18.0-193.80.1.el8_2, python3-perf 4.18.0-193.80.1.el8_2, +15 more
    fixed: vendor fix RHSA-2022:1213
  • Red Hat Enterprise Linux Client (v. 7) perf 3.10.0-1160.el7, kernel 3.10.0-1160.el7, bpftool 3.10.0-1160.el7, python-perf 3.10.0-1160.el7, kernel-tools 3.10.0-1160.el7, kernel-tools-libs 3.10.0-1160.el7, +2 more Red Hat Enterprise Linux Client Optional (v. 7) kernel-debuginfo-common-x86_64 3.10.0-1160.el7 Red Hat Enterprise Linux ComputeNode (v. 7) perf 3.10.0-1160.el7, kernel 3.10.0-1160.el7, bpftool 3.10.0-1160.el7, python-perf 3.10.0-1160.el7, kernel-tools 3.10.0-1160.el7, kernel-tools-libs 3.10.0-1160.el7, +2 more Red Hat Enterprise Linux ComputeNode Optional (v. 7) kernel-debuginfo-common-x86_64 3.10.0-1160.el7
    fixed: vendor fix RHSA-2020:4060
show 6 more
  • Red Hat Enterprise Linux for Real Time (v. 7) kernel-rt 3.10.0-1160.rt56.1131.el7, kernel-rt-trace 3.10.0-1160.rt56.1131.el7, kernel-rt-debuginfo-common-x86_64 3.10.0-1160.rt56.1131.el7 Red Hat Enterprise Linux for Real Time for NFV (v. 7) kernel-rt 3.10.0-1160.rt56.1131.el7, kernel-rt-kvm 3.10.0-1160.rt56.1131.el7, kernel-rt-trace 3.10.0-1160.rt56.1131.el7, kernel-rt-debug-kvm 3.10.0-1160.rt56.1131.el7, kernel-rt-trace-kvm 3.10.0-1160.rt56.1131.el7, kernel-rt-debuginfo-common-x86_64 3.10.0-1160.rt56.1131.el7
    fixed: vendor fix RHSA-2020:4062
  • Red Hat Enterprise Linux Real Time (v. 8) kernel-rt 4.18.0-240.rt7.54.el8, kernel-rt-core 4.18.0-240.rt7.54.el8, kernel-rt-modules 4.18.0-240.rt7.54.el8, kernel-rt-debug-core 4.18.0-240.rt7.54.el8, kernel-rt-debug-modules 4.18.0-240.rt7.54.el8, kernel-rt-modules-extra 4.18.0-240.rt7.54.el8, +2 more
    fixed: vendor fix RHSA-2020:4609
  • Red Hat Enterprise Linux Real Time EUS (v. 8.2) kernel-rt 4.18.0-193.80.1.rt13.130.el8_2, kernel-rt-core 4.18.0-193.80.1.rt13.130.el8_2, kernel-rt-modules 4.18.0-193.80.1.rt13.130.el8_2, kernel-rt-debug-core 4.18.0-193.80.1.rt13.130.el8_2, kernel-rt-debug-modules 4.18.0-193.80.1.rt13.130.el8_2, kernel-rt-modules-extra 4.18.0-193.80.1.rt13.130.el8_2, +2 more
    fixed: vendor fix RHSA-2022:1209
  • Red Hat Enterprise Linux Real Time for NFV (v. 8) kernel-rt 4.18.0-240.rt7.54.el8, kernel-rt-kvm 4.18.0-240.rt7.54.el8, kernel-rt-core 4.18.0-240.rt7.54.el8, kernel-rt-modules 4.18.0-240.rt7.54.el8, kernel-rt-debug-kvm 4.18.0-240.rt7.54.el8, kernel-rt-debug-core 4.18.0-240.rt7.54.el8, +4 more
    fixed: vendor fix RHSA-2020:4609
  • Red Hat Enterprise Linux Real Time for NFV EUS (v. 8.2) kernel-rt 4.18.0-193.80.1.rt13.130.el8_2, kernel-rt-kvm 4.18.0-193.80.1.rt13.130.el8_2, kernel-rt-core 4.18.0-193.80.1.rt13.130.el8_2, kernel-rt-modules 4.18.0-193.80.1.rt13.130.el8_2, kernel-rt-debug-kvm 4.18.0-193.80.1.rt13.130.el8_2, kernel-rt-debug-core 4.18.0-193.80.1.rt13.130.el8_2, +4 more
    fixed: vendor fix RHSA-2022:1209
  • Red Hat Enterprise Linux Server (v. 7) perf 3.10.0-1160.el7, kernel 3.10.0-1160.el7, bpftool 3.10.0-1160.el7, python-perf 3.10.0-1160.el7, kernel-kdump 3.10.0-1160.el7, kernel-tools 3.10.0-1160.el7, +7 more Red Hat Enterprise Linux Server Optional (v. 7) kernel-debuginfo-common-ppc64 3.10.0-1160.el7, kernel-debuginfo-common-x86_64 3.10.0-1160.el7, kernel-debuginfo-common-ppc64le 3.10.0-1160.el7 Red Hat Enterprise Linux Workstation (v. 7) perf 3.10.0-1160.el7, kernel 3.10.0-1160.el7, bpftool 3.10.0-1160.el7, python-perf 3.10.0-1160.el7, kernel-tools 3.10.0-1160.el7, kernel-tools-libs 3.10.0-1160.el7, +2 more Red Hat Enterprise Linux Workstation Optional (v. 7) kernel-debuginfo-common-x86_64 3.10.0-1160.el7
    fixed: vendor fix RHSA-2020:4060

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

0.40% chance of exploitation in the next 30 days, higher than 34% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
NVD 3.1 6.1 CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:H
NVD 2.0 3.6 AV:L/AC:L/Au:N/C:P/I:N/A:P

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.