CVE-2018-14600

An issue was discovered in libX11 through 1.6.5. The function XListExtensions in ListExt.c interprets a variable as signed instead of unsigned, resulting in an out-of-bounds write (of up to 128 bytes), leading to DoS or remote code execution.

Published: 2018-08-24 Last update: 2026-06-16 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2018-14600 is rated High Risk (71.1/100): CVSS Critical severity, with high exploitation likelihood (EPSS 9.71%, 95th percentile). EPSS ranks this CVE among the most likely to be exploited in the near term. High exploitation likelihood—assess exposure and prioritize remediation.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2018-14600

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-06-15 11.01% 9.71% -1.29%
2 2026-04-12 7.25% 11.01% +3.75%
3 2026-03-10 — 7.25% —

Full EPSS history (29 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2018-14600

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
9.8 3.0 CRITICAL
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 3.9 5.9 [email protected]
7.5 2.0 HIGH
AV:N/AC:L/Au:N/C:P/I:P/A:P Click to expand
Access vector (AV:N)
Can be exploited remotely over network reachability.
Access complexity (AC:L)
Exploitation conditions are straightforward and predictable.
Authentication (AU:N)
No authentication is required.
Confidentiality impact (C:P)
Partial confidentiality impact.
Integrity impact (I:P)
Partial integrity impact.
Availability impact (A:P)
Partial availability impact.
 10.0 6.4 [email protected]

Weakness enumeration for CVE-2018-14600

OS Trackers for CVE-2018-14600

vendor priority summary link
alpine critical CVE-2018-14600: 1 source package rows (libx11); 10 state rows across 10 repos (3.10-main, 3.11-main, 3.12-main, 3.17-main, 3.18-main, 3.19-main, 3.20-main, 3.21-main, 3.22-main, edge-main); fixed 10, open 0. https://security.alpinelinux.org/vuln/CVE-2018-14600
debian low CVE-2018-14600 low priority: Debian including 1 source packages (libx11), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 5. https://security-tracker.debian.org/tracker/CVE-2018-14600
gentoo normal CVE-2018-14600: 1 GLSA(s) (201811-01), 1 atom(s) (x11-libs/libX11); latest impact normal. https://bugs.gentoo.org/buglist.cgi?quicksearch=CVE-2018-14600
redhat medium — https://access.redhat.com/security/cve/CVE-2018-14600
suse high CVE-2018-14600 severity important: SUSE including 398 source package names (0.38.1:libX11-6-1.6.5-3.3.1, 0.38.1:libX11-data-1.6.5-3.3.1, …), 1136 product×package rows across 204 product lines (Container bci/openjdk, Container bci/openjdk-devel, … (204 product lines)): Fixed 905, Known Affected 231. https://www.suse.com/security/cve/CVE-2018-14600/
ubuntu medium CVE-2018-14600 medium priority: Ubuntu including 1 source packages (libx11), 4 status rows across 4 suites (bionic, trusty, upstream, xenial): released 4. https://ubuntu.com/security/CVE-2018-14600

Affected software / configurations for CVE-2018-14600

Vendor Product Version Raw CPE
x.org libx11 <= 1.6.5 cpe:2.3:a:x.org:libx11:*:*:*:*:*:*:*:*
canonical ubuntu_linux 12.04 cpe:2.3:o:canonical:ubuntu_linux:12.04:*:*:*:esm:*:*:*
canonical ubuntu_linux 14.04 cpe:2.3:o:canonical:ubuntu_linux:14.04:*:*:*:lts:*:*:*
canonical ubuntu_linux 16.04 cpe:2.3:o:canonical:ubuntu_linux:16.04:*:*:*:lts:*:*:*
canonical ubuntu_linux 18.04 cpe:2.3:o:canonical:ubuntu_linux:18.04:*:*:*:lts:*:*:*
debian debian_linux 8.0 cpe:2.3:o:debian:debian_linux:8.0:*:*:*:*:*:*:*

References for CVE-2018-14600

URL Tags
http://www.openwall.com/lists/oss-security/2018/08/21/6 Mailing List Third Party Advisory
http://www.securityfocus.com/bid/105177 Third Party Advisory VDB Entry
http://www.securitytracker.com/id/1041543 Third Party Advisory VDB Entry
https://access.redhat.com/errata/RHSA-2019:2079
https://bugzilla.suse.com/show_bug.cgi?id=1102068 Issue Tracking Patch Third Party Advisory
https://cgit.freedesktop.org/xorg/lib/libX11/commit/?id=dbf72805fd9d7b1846fe9a11b46f3994bfc27fea Patch Third Party Advisory
https://lists.debian.org/debian-lts-announce/2018/08/msg00030.html Mailing List Third Party Advisory
https://lists.x.org/archives/xorg-announce/2018-August/002916.html Third Party Advisory
https://security.gentoo.org/glsa/201811-01 Third Party Advisory
https://usn.ubuntu.com/3758-1/ Third Party Advisory
https://usn.ubuntu.com/3758-2/ Third Party Advisory
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