Predictive Vulnerability Intelligence.

Product

  • Product
  • Pricing
  • Documentation

Company

  • About
  • Partnerships
  • Blog
  • Support

Legal

  • Terms
  • Privacy
  • Data Licensing

© 2026 FAUCET Technologies LLC. All rights reserved.

CVE-2018-15856

20
FAUCET Score

CVE-2018-15856 describes an infinite loop vulnerability in xkbcommon versions prior to 0.8.1, specifically within the keymap parser (compose/parser.c). This flaw allows local attackers to trigger a denial of service by providing specially crafted keymap files, affecting Canonical Ubuntu Linux and xkbcommon itself. With a CVSS score of 5.5 (MEDIUM), the vulnerability requires local access and low privileges, but can lead to high availability impact. There is no evidence of active exploitation, public exploit code (Metasploit, Nuclei, ExploitDB), or significant community discussion or media coverage surrounding this CVE.

Impacted Technologies

VendorProductVersion(s)CPE
< 0.8.1CPE matchmatch criteria
cpe:2.3:a:xkbcommon:xkbcommon:*:*:*:*:*:*:*:*
14.04CPE matchmatch criteria
cpe:2.3:o:canonical:ubuntu_linux:14.04:*:*:*:lts:*:*:*
16.04CPE matchmatch criteria
cpe:2.3:o:canonical:ubuntu_linux:16.04:*:*:*:lts:*:*:*
18.04CPE matchmatch criteria
cpe:2.3:o:canonical:ubuntu_linux:18.04:*:*:*:lts:*:*:*

CVSS Data

CVSS version used by this source: 3.0

5.5MEDIUM

CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Attack Vector
LOCAL
Attack Complexity
LOW
Privileges Required
LOW
User Interaction
NONE
Scope
UNCHANGED
Confidentiality Impact
NONE
Integrity Impact
NONE
Availability Impact
HIGH
Exploitability Score
1.8
Impact Score
3.6
CvssVersion
3.0

Exploit Intelligence

EPSS Score
0.43%
Probability of exploitation in next 30 days
EPSS Percentile
35.1%
Percentile rank of EPSS score among Peer Group
As of 2026-07-25
Model: v2026.06.15
This CVE's current EPSS score of 0.0043 is in the 89th percentile among its peer group of 15,937 CVEs.

Social Chatter

The average CVE in this peer group has 0.0 Twitter, 0.0 Reddit, 0.0 Bluesky, 0.0 Mastodon, and 0.1 GitHub mentions.

Media Mentions

No media coverage found for this CVE.

The average CVE in this peer group has 0.1 InfoSec Media, 0.0 Vendor Blog, and 0.0 Security Researcher mentions.

Remediation

Patch Available

Vendor Patches (9)

github_advisorypatch availablevia nvd_reference
View patch
redhatpatch availablevia redhat_api
Product: Red Hat Enterprise Linux 7Fixed in: gdm-1:3.28.2-16.el7
View patch
redhatpatch availablevia redhat_api
Product: Red Hat Enterprise Linux 7Fixed in: libX11-0:1.6.7-2.el7
View patch
redhatpatch availablevia redhat_api
Product: Red Hat Enterprise Linux 7Fixed in: libxkbcommon-0:0.7.1-3.el7
View patch
redhatpatch availablevia redhat_api
Product: Red Hat Enterprise Linux 7Fixed in: mesa-libGLw-0:8.0.0-5.el7
View patch
redhatpatch availablevia redhat_api
Product: Red Hat Enterprise Linux 7Fixed in: xorg-x11-drv-ati-0:19.0.1-2.el7
View patch
redhatpatch availablevia redhat_api
Product: Red Hat Enterprise Linux 7Fixed in: xorg-x11-drv-vesa-0:2.4.0-3.el7
View patch
redhatpatch availablevia redhat_api
Product: Red Hat Enterprise Linux 7Fixed in: xorg-x11-drv-wacom-0:0.36.1-3.el7
View patch
redhatpatch availablevia redhat_api
Product: Red Hat Enterprise Linux 7Fixed in: xorg-x11-server-0:1.20.4-7.el7
View patch

Vendor Advisories (1)

redhatCVE-2018-15856Low

libxkbcommon: Infinite loop when reaching EOL unexpectedly resulting in a crash

Mar 12, 2018

References

access.redhat.com / errata/RHSA-2019:2079
github.com / xkbcommon/libxkbcommon/commit/842e4351c2c97de6051cab6ce36b4a81e709a0e1
PatchThird Party Advisory
lists.freedesktop.org / archives/wayland-devel/2018-August/039232.html
Mailing ListPatchThird Party Advisory
security.gentoo.org / glsa/201810-05
Third Party Advisory
usn.ubuntu.com / 3786-1
Third Party Advisory
usn.ubuntu.com / 3786-2
Third Party Advisory