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Fencer Vulns
high 7.8

CVE-2020-25220 json

The Linux kernel 4.9.x before 4.9.233, 4.14.x before 4.14.194, and 4.19.x before 4.19.140 has a use-after-free because skcd->no_refcnt was…

published 2020-09-10 6 y ago modified 2026-06-17 4 mo ago also EUVD-2020-17910

cvss
7.8
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 39%
public exploits
0
none known

Summary

The Linux kernel 4.9.x before 4.9.233, 4.14.x before 4.14.194, and 4.19.x before 4.19.140 has a use-after-free because skcd->no_refcnt was not considered during a backport of a CVE-2020-14356 patch. This is related to the cgroups feature.

Patch / fix

  • linux linux_kernel 4.9.233, 4.14.194, 4.19.140
  • linux Ubuntu 18.04 LTS 4.15.0-118.119
  • linux-aws Ubuntu 18.04 LTS 4.15.0-1083.87
  • linux-gcp Ubuntu 16.04 LTS 4.15.0-1084.95~16.04.1
  • linux-hwe Ubuntu 16.04 LTS 4.15.0-118.119~16.04.1
  • linux-kvm Ubuntu 18.04 LTS 4.15.0-1075.76
  • linux-oem Ubuntu 18.04 LTS 4.15.0-1097.107
  • linux-azure Ubuntu 16.04 LTS 4.15.0-1096.106~16.04.1
  • linux-oracle Ubuntu 16.04 LTS 4.15.0-1054.58~16.04.1

ubuntu advisories UBUNTU-CVE-2020-25220

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

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-2020-25220 updated cvss 7.0

kernel: use-after-free because skcd->no_refcnt was not considered during the backport of CVE-2020-14356

  • 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, bpftool, kernel-rt, kernel-alt, python-perf, +9 more Red Hat Enterprise Linux 8 perf, kernel, bpftool, kernel-rt, kernel-core, kernel-tools, +29 more Red Hat Enterprise MRG 2 kernel-rt, mrg-rt-release, kernel-rt-trace, kernel-rt-vanilla, kernel-rt-firmware
    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

0.45% chance of exploitation in the next 30 days, higher than 39% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
NVD 3.1 7.8 CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
NVD 2.0 7.2 AV:L/AC:L/Au:N/C:C/I:C/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.