What is CVE-2017-18221?

CVE-2017-18221 is a medium-severity vulnerability in Linux Kernel, classified under Improper Input Validation. CVSS score: 5.5/10. Published 2018-03-07.

How severe is CVE-2017-18221?

Medium severity. CVSS v3 base score is 5.5 out of 10.

Improper input validation in Linux Kernel

CVE-2017-18221

The __munlock_pagevec function in mm/mlock.c in the Linux kernel before 4.11.4 allows local users to cause a denial of service (NR_MLOCK accounting corruption) via crafted use of mlockall and munlockall system calls.

Vulnerability class: Drupalgeddon 2 (CVE-2018-7600)

Published 2018-03-07 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 5.5 (Medium). Vector: CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H.

EPSS exploit prediction

EPSS: 0.005 (37.3th percentile), scored 2026-10-07.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 37th percentile — 37.3% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.005 · newest: 0.005 · change: 0.000

Affected products

Linux Kernel

Weakness classification (CWE)

CWE-20 — Improper Input Validation

References

github.com/torvalds/linux/commit/70feee0e1ef331b22cc51f383d532a0d043fbdcc (Patch, Third Party Advisory)
usn.ubuntu.com/3655-1/ (vendor-advisory)
git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/ (Patch, Vendor Advisory)
www.kernel.org/pub/linux/kernel/v4.x/ChangeLog-4.11.4 (Release Notes, Vendor Advisory)
usn.ubuntu.com/3655-2/ (vendor-advisory)
www.securityfocus.com/bid/103321 (VDB Entry, Third Party Advisory, vdb-entry)

Frequently asked questions

What is CVE-2017-18221?: CVE-2017-18221 is a medium-severity vulnerability in Linux Kernel, classified under Improper Input Validation. CVSS score: 5.5/10. Published 2018-03-07.
How severe is CVE-2017-18221?: Medium severity. CVSS v3 base score is 5.5 out of 10.