No exploitation reportedFix available

CVE-2018-20784

Q: Is CVE-2018-20784 actively exploited?

Active exploitation of CVE-2018-20784 has not been confirmed. Its EPSS score was 4.2% on 2026-10-22, the estimated probability of exploitation in the next 30 days.

Q: What is the CVSS score for CVE-2018-20784?

CVE-2018-20784 has a CVSS v3 base score of 9.8 (CRITICAL severity), with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

No exploitation reported by the sources we read.

Published2019-02-22
Fixed in4.20.2 · 4.19.15 · 4.14.93
WeaknessCWE-835

Am I affected?

With a domain, we read the version its public headers and pages expose. A distribution build can carry the fix under an older number.

Description

In the Linux kernel before 4.20.2, kernel/sched/fair.c mishandles leaf cfs_rq's, which allows attackers to cause a denial of service (infinite loop in update_blocked_averages) or possibly have unspecified other impact by inducing a high load.

Timeline

dates in UTC

2019-02-2215:29CVE publishedNVD

Observed activity

isMalicious corpus · updated 2026-10-23 18:48 UTC

Indicators tagged with this CVE, per day0 indicators over 7 days

Block these indicators

Firewall list (EDL, text): https://api.ismalicious.com/edl/cve/CVE-2018-20784?format=txt
CSV export: https://api.ismalicious.com/edl/cve/CVE-2018-20784?format=csv
TAXII collection of exploited CVEs
The EDL and CSV take an API key on the Pro plan.

Versions per branch

NVD

Linux linux kernel

Branch	Affected	Fixed in	Source
4.20	≥ 4.20, < 4.20.2	4.20.2	NVD
4.19	≥ 4.19, < 4.19.15	4.19.15	NVD
4.x	≥ 4.13, < 4.14.93	4.14.93	NVD
5.0	= 5.0	no fix published	NVD

Canonical ubuntu linux

Branch	Affected	Fixed in	Source
14.4	= 14.04	no fix published	NVD
16.4	= 16.04	no fix published	NVD
18.4	= 18.04	no fix published	NVD

Redhat enterprise linux

Branch	Affected	Fixed in	Source
8.0	= 8.0	no fix published	NVD

1 more product in the sources.

as publishedRanges as NVD and OSV publish them; a distribution’s build can be fixed under an older number.

Fix

Update Linux linux kernel to 4.20.2 · 4.19.15 · 4.14.93

Advisories and patches

git.kernel.orgPatch · Vendor Advisory
cdn.kernel.orgRelease Notes · Vendor Advisory
github.comPatch

Detection

Nuclei template: none so far
Exploit-DB: no entry
Proof-of-concept repositories: none listed

Sources

NVDCVSS 3.19.8read 2026-10-23
NVDCVSS 2.07.5read 2026-10-23
NVDweakness (CWE)CWE-835read 2026-10-23
FIRST EPSSEPSS score4.2 %2026-10-22

Technical details

CVSS v3 Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Published: 2019-02-22
Last Modified: 2026-06-17
NVD status: Modified

Frequently asked questions

What is CVE-2018-20784?

Is CVE-2018-20784 actively exploited?

Active exploitation of CVE-2018-20784 has not been confirmed. Its EPSS score was 4.2% on 2026-10-22, the estimated probability of exploitation in the next 30 days.

What is the CVSS score for CVE-2018-20784?

CVE-2018-20784 has a CVSS v3 base score of 9.8 (CRITICAL severity), with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

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