What is CVE-2018-15127?

CVE-2018-15127 is a critical-severity vulnerability in Libvnc Project Libvncserver, classified under Out-of-bounds Write. CVSS score: 9.8/10. Published 2018-12-19.

How severe is CVE-2018-15127?

Critical severity. CVSS v3 base score is 9.8 out of 10.

Buffer overflow in Libvnc Project Libvncserver

CVE-2018-15127

LibVNC before commit 502821828ed00b4a2c4bef90683d0fd88ce495de contains heap out-of-bound write vulnerability in server code of file transfer extension that can result remote code execution

Vulnerability class: Buffer Overflow

Published 2018-12-19 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 9.8 (Critical). Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

EPSS exploit prediction

EPSS: 0.151 (96.7th percentile), scored 2026-10-18.

Moderate probability of exploitation in the next 30 days — watch for active exploitation reports. 97th percentile — 96.7% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.151 · newest: 0.151 · change: 0.000

Affected products

Libvnc Project Libvncserver
Canonical Ubuntu Linux — versions 14.04, 16.04, 18.04
Debian Linux — versions 8.0, 9.0
Red Hat Enterprise Linux Desktop — versions 7.0
Red Hat Enterprise Linux Server — versions 7.0
Red Hat Enterprise Linux Server Aus — versions 7.6
Red Hat Enterprise Linux Server Eus — versions 7.6
Red Hat Enterprise Linux Server Tus — versions 7.6
Red Hat Enterprise Linux Workstation — versions 7.0
Libvnc — versions commit 502821828ed00b4a2c4bef90683d0fd88ce495de

Weakness classification (CWE)

CWE-787 — Out-of-bounds Write

References

www.debian.org/security/2019/dsa-4383 (vendor-advisory, Third Party Advisory)
lists.debian.org/debian-lts-announce/2018/12/msg00017.html (mailing-list, Mailing List, Third Party Advisory)
ics-cert.kaspersky.com/advisories/klcert-advisories/2018/12/19/klcert-18-028-li… (Third Party Advisory)
usn.ubuntu.com/3877-1/ (vendor-advisory, Third Party Advisory)
access.redhat.com/errata/RHSA-2019:0059 (vendor-advisory, Third Party Advisory)
lists.debian.org/debian-lts-announce/2019/10/msg00042.html (mailing-list)
usn.ubuntu.com/4547-1/ (vendor-advisory)
usn.ubuntu.com/4587-1/ (vendor-advisory)

Frequently asked questions

What is CVE-2018-15127?: CVE-2018-15127 is a critical-severity vulnerability in Libvnc Project Libvncserver, classified under Out-of-bounds Write. CVSS score: 9.8/10. Published 2018-12-19.
How severe is CVE-2018-15127?: Critical severity. CVSS v3 base score is 9.8 out of 10.