What is CVE-2018-1071?

CVE-2018-1071 is a medium-severity vulnerability in Zsh, classified under Stack-based Buffer Overflow. CVSS score: 5.5/10. Published 2018-03-09.

How severe is CVE-2018-1071?

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

Is CVE-2018-1071 known to be exploited?

1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.

Buffer overflow in Zsh

CVE-2018-1071

zsh through version 5.4.2 is vulnerable to a stack-based buffer overflow in the exec.c:hashcmd() function. A local attacker could exploit this to cause a denial of service.

Vulnerability class: Buffer Overflow

Published 2018-03-09 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 5.5 (Medium). Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H.

EPSS exploit prediction

EPSS: 0.004 (34.6th percentile), scored 2026-10-01.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 35th percentile — 34.6% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.004 · newest: 0.004 · change: 0.000

Affected products

Zsh — versions 5.4.2
Canonical Ubuntu Linux — versions 14.04, 16.04, 17.10
Debian Linux — versions 7.0
Red Hat Enterprise Linux Desktop — versions 7.0
Red Hat Enterprise Linux Server — versions 7.0
Red Hat Enterprise Linux Workstation — versions 7.0

Weakness classification (CWE)

Public proof-of-concept exploits

ARPSyndicate/cvemon

References

bugzilla.redhat.com/show_bug.cgi (Third Party Advisory, Issue Tracking)
usn.ubuntu.com/3608-1/ (vendor-advisory, Third Party Advisory)
www.securityfocus.com/bid/103359 (VDB Entry, Third Party Advisory, vdb-entry)
security.gentoo.org/glsa/201805-10 (vendor-advisory, Third Party Advisory)
lists.debian.org/debian-lts-announce/2018/03/msg00038.html (mailing-list, Mailing List, Third Party Advisory)
access.redhat.com/errata/RHSA-2018:3073 (vendor-advisory, Third Party Advisory)
lists.debian.org/debian-lts-announce/2020/12/msg00000.html (mailing-list)

Frequently asked questions

What is CVE-2018-1071?: CVE-2018-1071 is a medium-severity vulnerability in Zsh, classified under Stack-based Buffer Overflow. CVSS score: 5.5/10. Published 2018-03-09.
How severe is CVE-2018-1071?: Medium severity. CVSS v3 base score is 5.5 out of 10.
Is CVE-2018-1071 known to be exploited?: 1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.