CVE-2018-14598

An issue was discovered in XListExtensions in ListExt.c in libX11 through 1.6.5. A malicious server can send a reply in which the first string overflows, causing a variable to be set to NULL that will be freed later on, leading to DoS (segmentation fault).

Published: 2018-08-24 Last update: 2026-06-17 Assigner: [email protected] Source: [email protected]

Conclusion & alert: CVE-2018-14598 is rated Moderate Risk (63.5/100): CVSS High severity, with high exploitation likelihood (EPSS 4.76%, 91th percentile). Core evidence: EPSS ranks this CVE among the most likely to be exploited in the near term. EPSS rose +1.73% over the last day, indicating growing attacker interest. Mandatory action: 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-2018-14598

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 3.03% 4.76% +1.73%
2 2026-04-12 1.10% 3.03% +1.93%
3 2026-02-27 1.10%

Full EPSS history (24 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2018-14598

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
7.5 3.0 HIGH
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/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:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
3.9 3.6 [email protected]
5.0 2.0 MEDIUM
AV:N/AC:L/Au:N/C:N/I:N/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:N)
No confidentiality impact.
Integrity impact (I:N)
No integrity impact.
Availability impact (A:P)
Partial availability impact.
10.0 2.9 [email protected]

Weakness enumeration for CVE-2018-14598

OS Trackers for CVE-2018-14598

vendor priority summary link
alpine high CVE-2018-14598: 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-2018-14598
debian low CVE-2018-14598 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-2018-14598
gentoo normal CVE-2018-14598: 1 GLSA(s) (201811-01), 1 atom(s) (x11-libs/libX11); latest impact normal. https://bugs.gentoo.org/buglist.cgi?quicksearch=CVE-2018-14598
redhat medium https://access.redhat.com/security/cve/CVE-2018-14598
suse medium CVE-2018-14598 severity moderate: 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-2018-14598/
ubuntu medium CVE-2018-14598 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-2018-14598

Affected software / configurations for CVE-2018-14598

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:*:*:*:*:*:*:*
fedoraproject fedora 28 cpe:2.3:o:fedoraproject:fedora:28:*:*:*:*:*:*:*

References for CVE-2018-14598

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=1102073 Issue Tracking Patch Third Party Advisory
https://cgit.freedesktop.org/xorg/lib/libX11/commit/?id=e83722768fd5c467ef61fa159e8c6278770b45c2 Patch Third Party Advisory
https://lists.debian.org/debian-lts-announce/2018/08/msg00030.html Third Party Advisory
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/YGARUV66TS5OOSLR5A76BUB7SDV6GO4F/
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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