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TI-2018-14755 Aliases CVE-2018-20784GHSA-qg2g-rfcv-qffx

In the Linux kernel before 4.20.2, kernel/sched/fair.c mishandles leaf cfs_rq's, which…

Priority MEDIUM 49CWE-835Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
None
Attack complexity
Low
Impact type
Denial of service
Confidentiality · integrity · availability
High · High · High
Fix status
Partial Red Hat: 4 fixed, 1 without a fix

Attack profile from CVSS 3.1 · NVD. Fix status from CNA and Red Hat. Impact type from CWE-835.

Summary

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.

Why it matters now

EPSS 0.04173 90th percentileScored 2026-11-07
Fix Partial Red Hat: 2 advisoriesRed Hat: 4 fixed, 1 without a fix

SSVC decision points

Not available: CISA has not published SSVC decision points for this record.

Affected products

VendorProductAffected versionsFixed inStatusSource
——all versions—No fix listedCNA
  • — Vendor— Affected all versions Fixed in — No fix listed CNA

CPE configurations NVD · 7

CPEVersionsRoleVendor
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*4.13 to before 4.14.93; 4.19 to before 4.19.15; 4.20 to before 4.20.2VulnerableLinux
cpe:2.3:o:linux:linux_kernel:5.0:rc1:*:*:*:*:*:*5.0 rc1VulnerableLinux
cpe:2.3:o:canonical:ubuntu_linux:14.04:*:*:*:esm:*:*:*14.04VulnerableCanonical
cpe:2.3:o:canonical:ubuntu_linux:16.04:*:*:*:esm:*:*:*16.04VulnerableCanonical
cpe:2.3:o:canonical:ubuntu_linux:18.04:*:*:*:lts:*:*:*18.04VulnerableCanonical
cpe:2.3:o:redhat:enterprise_linux:8.0:*:*:*:*:*:*:*8.0VulnerableRed Hat
cpe:2.3:o:redhat:enterprise_linux_for_real_time:8:*:*:*:*:*:*:*8VulnerableRed Hat
  • cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* Versions 4.13 to before 4.14.93; 4.19 to before 4.19.15; 4.20 to before 4.20.2 Vulnerable ·Linux
  • cpe:2.3:o:linux:linux_kernel:5.0:rc1:*:*:*:*:*:* Versions 5.0 rc1 Vulnerable ·Linux
  • cpe:2.3:o:canonical:ubuntu_linux:14.04:*:*:*:esm:*:*:* Versions 14.04 Vulnerable ·Canonical
  • cpe:2.3:o:canonical:ubuntu_linux:16.04:*:*:*:esm:*:*:* Versions 16.04 Vulnerable ·Canonical
  • cpe:2.3:o:canonical:ubuntu_linux:18.04:*:*:*:lts:*:*:* Versions 18.04 Vulnerable ·Canonical
  • cpe:2.3:o:redhat:enterprise_linux:8.0:*:*:*:*:*:*:* Versions 8.0 Vulnerable ·Red Hat
  • cpe:2.3:o:redhat:enterprise_linux_for_real_time:8:*:*:*:*:*:*:* Versions 8 Vulnerable ·Red Hat

Remediation

Red Hat 2 advisories

  • RHSA-2019:1971 Released 2019-07-30 · Red Hat rating Important
    kernel-rt security and bug fix update
    • Red Hat Enterprise Linux Real Time (v. 8) kernel-rt-4.18.0-80.7.1.rt9.153.el8_0, kernel-rt-core-4.18.0-80.7.1.rt9.153.el8_0, kernel-rt-debug-4.18.0-80.7.1.rt9.153.el8_0 +7
    • Red Hat Enterprise Linux Real Time for NFV (v. 8) kernel-rt-4.18.0-80.7.1.rt9.153.el8_0, kernel-rt-core-4.18.0-80.7.1.rt9.153.el8_0, kernel-rt-debug-4.18.0-80.7.1.rt9.153.el8_0 +9
  • RHSA-2019:1959 Released 2019-07-30 · Red Hat rating Important
    kernel security, bug fix, and enhancement update
    • Red Hat CodeReady Linux Builder (v. 8) kernel-tools-libs-devel-4.18.0-80.7.1.el8_0
    • Red Hat Enterprise Linux BaseOS (v. 8) bpftool-4.18.0-80.7.1.el8_0, kernel-4.18.0-80.7.1.el8_0, kernel-abi-whitelists-4.18.0-80.7.1.el8_0 +19

Vendor assessments

Red Hat

Red Hat rating: Moderate. Red Hat's page for this CVE →

ProductStatusPlan or fix
Red Hat Enterprise Linux 7AffectedNo fix planned: Will not fix
Red Hat CodeReady Linux Builder (v. 8)Fixed RHSA-2019:1959
Red Hat Enterprise Linux BaseOS (v. 8)Fixed RHSA-2019:1959
Red Hat Enterprise Linux Real Time (v. 8)Fixed RHSA-2019:1971
Red Hat Enterprise Linux Real Time for NFV (v. 8)Fixed RHSA-2019:1971
Not affected: 4 products
  • Red Hat Enterprise Linux 5
  • Red Hat Enterprise Linux 6
  • Red Hat Enterprise Linux 7
  • Red Hat Enterprise MRG 2

Timeline

  1. 2026-10-02 Threatist record created from CVE-2018-20784
  2. 2026-10-03 Alias added: GHSA-qg2g-rfcv-qffx

References

Patch 2

Advisory 7

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences