CVE-2018-20836

Name: CVE-2018-20836
Creator: NVD / NIST
Published: 2019-05-07T14:29:00.303+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

HIGHCVSS 8.1/10EPSS 5.11%

Last modified Jun 17, 2026

CVE-2018-20836 is a high-severity vulnerability rated 8.1/10 on the CVSS scale. An issue was discovered in the Linux kernel before 4.20. There is a race condition in smp_task_timedout() and smp_task_done() in drivers/scsi/libsas/sas_expander.c, leading to a use-after-free.. EPSS estimates a 5.11% chance of exploitation in the next 30 days.

Description

An issue was discovered in the Linux kernel before 4.20. There is a race condition in smp_task_timedout() and smp_task_done() in drivers/scsi/libsas/sas_expander.c, leading to a use-after-free.

Metrics

CVSS 3.1

8.1/10

CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H

EPSS Probability

5.11%

91.3th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

Vendor	Product	Versions
Linux	Linux Kernel	< 3.16.72
Linux	Linux Kernel	>= 3.17, < 3.18.140
Linux	Linux Kernel	>= 3.19, < 4.4.180
Linux	Linux Kernel	>= 4.5, < 4.9.175
Linux	Linux Kernel	>= 4.10, < 4.14.118
Linux	Linux Kernel	>= 4.15, < 4.19.42
Canonical	Ubuntu Linux	16.04
Debian	Debian Linux	8.0
Debian	Debian Linux	9.0
Debian	Debian Linux	10.0
F5	Traffix Signaling Delivery Controller	5.0.0
F5	Traffix Signaling Delivery Controller	5.1.0
Netapp	Active Iq Unified Manager	>= 9.5
Netapp	Snapprotect	All versions
Netapp	Solidfire \& Hci Management Node	All versions
Netapp	Solidfire \& Hci Storage Node	All versions
Netapp	Storage Replication Adapter For Clustered Data Ontap	All versions
Netapp	Vasa Provider For Clustered Data Ontap	>= 7.2
Netapp	Virtual Storage Console	>= 7.2
Netapp	Hci Compute Node	All versions
Opensuse	Leap	15.0
Opensuse	Leap	15.1

References

http://lists.opensuse.org/opensuse-security-announce/2019-07/msg00014.htmlMailing List, Third Party Advisory
http://lists.opensuse.org/opensuse-security-announce/2019-07/msg00025.htmlMailing List, Third Party Advisory
http://www.securityfocus.com/bid/108196Third Party Advisory, VDB Entry
https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=b90cd6f2b905905fb42671009dc0e27c310a16aePatch, Vendor Advisory
https://github.com/torvalds/linux/commit/b90cd6f2b905905fb42671009dc0e27c310a16aePatch, Vendor Advisory
https://lists.debian.org/debian-lts-announce/2019/08/msg00016.htmlMailing List, Third Party Advisory
https://lists.debian.org/debian-lts-announce/2019/08/msg00017.htmlMailing List, Third Party Advisory
https://seclists.org/bugtraq/2019/Aug/13Mailing List, Third Party Advisory
https://seclists.org/bugtraq/2019/Aug/18Mailing List, Third Party Advisory
https://security.netapp.com/advisory/ntap-20190719-0003/Third Party Advisory
https://support.f5.com/csp/article/K11225249Third Party Advisory
https://usn.ubuntu.com/4076-1/Third Party Advisory
https://www.debian.org/security/2019/dsa-4495Third Party Advisory
https://www.debian.org/security/2019/dsa-4497Third Party Advisory
http://lists.opensuse.org/opensuse-security-announce/2019-07/msg00014.htmlMailing List, Third Party Advisory
http://lists.opensuse.org/opensuse-security-announce/2019-07/msg00025.htmlMailing List, Third Party Advisory
http://www.securityfocus.com/bid/108196Third Party Advisory, VDB Entry
https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=b90cd6f2b905905fb42671009dc0e27c310a16aePatch, Vendor Advisory
https://github.com/torvalds/linux/commit/b90cd6f2b905905fb42671009dc0e27c310a16aePatch, Vendor Advisory
https://lists.debian.org/debian-lts-announce/2019/08/msg00016.htmlMailing List, Third Party Advisory
https://lists.debian.org/debian-lts-announce/2019/08/msg00017.htmlMailing List, Third Party Advisory
https://seclists.org/bugtraq/2019/Aug/13Mailing List, Third Party Advisory
https://seclists.org/bugtraq/2019/Aug/18Mailing List, Third Party Advisory
https://security.netapp.com/advisory/ntap-20190719-0003/Third Party Advisory
https://support.f5.com/csp/article/K11225249Third Party Advisory
https://usn.ubuntu.com/4076-1/Third Party Advisory
https://www.debian.org/security/2019/dsa-4495Third Party Advisory
https://www.debian.org/security/2019/dsa-4497Third Party Advisory

Timeline

Published: May 7, 2019
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2018-20836?

An issue was discovered in the Linux kernel before 4.20. There is a race condition in smp_task_timedout() and smp_task_done() in drivers/scsi/libsas/sas_expander.c, leading to a use-after-free.

How severe is CVE-2018-20836?

CVE-2018-20836 has a CVSS score of 8.1/10 (HIGH severity). The EPSS model estimates a 5.11% probability of exploitation in the next 30 days.

How do I fix CVE-2018-20836?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2018-20836?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST