CVE-2018-20784
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.
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (4.17%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
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.
- CVSS 3.1
- 9.8 CRITICALCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
- EPSS
- 4.17% probability · 91th percentile
- Public exploits
- None in Exploit-DB
- CISA KEV
- Not listed
- Weakness
- CWE-835
- Affected
- linux/linux kernel · canonical/ubuntu linux · redhat/enterprise linux · redhat/enterprise linux for real time
- Source
- cve@mitre.org
EPSS 4.2% since 27 October 2026; no change recorded yet. Points are recorded when the score first appears and whenever it moves by a percentage point or more.
References
- http://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=c40f7d74c741a907cfaeb73a7697081881c497d0Patch, Vendor Advisory
- https://access.redhat.com/errata/RHSA-2019:1959Third Party Advisory
- https://access.redhat.com/errata/RHSA-2019:1971Third Party Advisory
- https://cdn.kernel.org/pub/linux/kernel/v4.x/ChangeLog-4.20.2Release Notes, Vendor Advisory
- https://github.com/torvalds/linux/commit/c40f7d74c741a907cfaeb73a7697081881c497d0Patch, Third Party Advisory
- https://usn.ubuntu.com/4115-1/Third Party Advisory
- https://usn.ubuntu.com/4118-1/Third Party Advisory
- https://usn.ubuntu.com/4211-1/Third Party Advisory
- https://usn.ubuntu.com/4211-2/Third Party Advisory
- http://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=c40f7d74c741a907cfaeb73a7697081881c497d0Patch, Vendor Advisory
- https://access.redhat.com/errata/RHSA-2019:1959Third Party Advisory
- https://access.redhat.com/errata/RHSA-2019:1971Third Party Advisory
- https://cdn.kernel.org/pub/linux/kernel/v4.x/ChangeLog-4.20.2Release Notes, Vendor Advisory
- https://github.com/torvalds/linux/commit/c40f7d74c741a907cfaeb73a7697081881c497d0Patch, Third Party Advisory
- https://usn.ubuntu.com/4115-1/Third Party Advisory
- https://usn.ubuntu.com/4118-1/Third Party Advisory
- https://usn.ubuntu.com/4211-1/Third Party Advisory
- https://usn.ubuntu.com/4211-2/Third Party Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.