What is CVE-2020-14402?

CVE-2020-14402 is a medium-severity vulnerability in Libvnc Project Libvncserver, classified under Out-of-bounds Write. CVSS score: 5.4/10. Published 2020-06-17.

How severe is CVE-2020-14402?

Medium severity. CVSS v3 base score is 5.4 out of 10.

Is CVE-2020-14402 known to be exploited?

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

Buffer overflow in Libvnc Project Libvncserver

CVE-2020-14402

An issue was discovered in LibVNCServer before 0.9.13. libvncserver/corre.c allows out-of-bounds access via encodings.

Vulnerability class: Buffer Overflow

Published 2020-06-17 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 5.4 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:L.

EPSS exploit prediction

EPSS: 0.019 (78.7th percentile), scored 2026-09-29.

Low probability of exploitation in the next 30 days, but still tracked. 79th percentile — 78.7% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.019 · newest: 0.019 · change: 0.000

Affected products

Weakness classification (CWE)

CWE-787 — Out-of-bounds Write

Public proof-of-concept exploits

ARPSyndicate/cvemon

References

github.com/LibVNC/libvncserver/compare/LibVNCServer-0.9.12...LibVNCServer-0.9.13 (Third Party Advisory, Release Notes)
github.com/LibVNC/libvncserver/commit/74e8a70f2c9a5248d6718ce443e07c7ed314dfff (Patch, Third Party Advisory)
lists.debian.org/debian-lts-announce/2020/06/msg00035.html (mailing-list, Mailing List, Third Party Advisory)
lists.opensuse.org/opensuse-security-announce/2020-07/msg00033.html (vendor-advisory, Mailing List, Third Party Advisory)
lists.opensuse.org/opensuse-security-announce/2020-07/msg00055.html (vendor-advisory, Mailing List, Third Party Advisory)
lists.opensuse.org/opensuse-security-announce/2020-07/msg00066.html (vendor-advisory, Third Party Advisory, Issue Tracking)
usn.ubuntu.com/4434-1/ (vendor-advisory, Third Party Advisory)
lists.debian.org/debian-lts-announce/2020/08/msg00045.html (mailing-list, Mailing List, Third Party Advisory)
usn.ubuntu.com/4573-1/ (vendor-advisory, Third Party Advisory)
cert-portal.siemens.com/productcert/pdf/ssa-390195.pdf (Patch, Third Party Advisory)

Frequently asked questions

What is CVE-2020-14402?: CVE-2020-14402 is a medium-severity vulnerability in Libvnc Project Libvncserver, classified under Out-of-bounds Write. CVSS score: 5.4/10. Published 2020-06-17.
How severe is CVE-2020-14402?: Medium severity. CVSS v3 base score is 5.4 out of 10.
Is CVE-2020-14402 known to be exploited?: 1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.