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Vulnerability record · CVE-2018-20749 · published 30 January 2019

CVE-2018-20749: Libvnc project libvncserver out-of-bounds write vulnerability

LLibvnc Project · Libvncserver

LibVNC before 0.9.12 contains a heap out-of-bounds write vulnerability in libvncserver/rfbserver.c. The fix for CVE-2018-15127 was incomplete.

9.8 CVSS 3.1 Critical EPSS 3.2% · top 12.1% CWE-787 · Out-of-bounds write
9.8CVSS 3.1 base score, v2 7.5
3.2%EPSS exploitation probability, 30 days
NoNot in CISA KEV
9Affected product versions listed by NVD
20References, 2 tagged exploit
17 Jun 2026Last modified by NVD

Description

LibVNC before 0.9.12 contains a heap out-of-bounds write vulnerability in libvncserver/rfbserver.c. The fix for CVE-2018-15127 was incomplete.

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Affected products

9 vulnerable configurations from NVD's CPE data, grouped by vendor and product.

References

LinkTags
http://www.securityfocus.com/bid/106825 Broken Link
https://cert-portal.siemens.com/productcert/pdf/ssa-390195.pdf PatchThird Party Advisory
https://github.com/LibVNC/libvncserver/commit/15bb719c03cc70f14c36a843dcb16ed69b405707 PatchThird Party Advisory
https://github.com/LibVNC/libvncserver/issues/273 Issue TrackingThird Party Advisory
https://lists.debian.org/debian-lts-announce/2019/01/msg00029.html Third Party Advisory
https://lists.debian.org/debian-lts-announce/2019/10/msg00042.html Mailing ListThird Party Advisory
https://usn.ubuntu.com/3877-1/ Third Party Advisory
https://usn.ubuntu.com/4547-1/ Third Party Advisory
https://usn.ubuntu.com/4587-1/ Third Party Advisory
https://www.openwall.com/lists/oss-security/2018/12/10/8 ExploitMailing ListThird Party Advisory
http://www.securityfocus.com/bid/106825 Broken Link
https://cert-portal.siemens.com/productcert/pdf/ssa-390195.pdf PatchThird Party Advisory
https://github.com/LibVNC/libvncserver/commit/15bb719c03cc70f14c36a843dcb16ed69b405707 PatchThird Party Advisory
https://github.com/LibVNC/libvncserver/issues/273 Issue TrackingThird Party Advisory
https://lists.debian.org/debian-lts-announce/2019/01/msg00029.html Third Party Advisory
https://lists.debian.org/debian-lts-announce/2019/10/msg00042.html Mailing ListThird Party Advisory
https://usn.ubuntu.com/3877-1/ Third Party Advisory
https://usn.ubuntu.com/4547-1/ Third Party Advisory
https://usn.ubuntu.com/4587-1/ Third Party Advisory
https://www.openwall.com/lists/oss-security/2018/12/10/8 ExploitMailing ListThird Party Advisory

Track CVE-2018-20749 inside VULONE

Watch it alongside the ransomware crews, C2 infrastructure and forum chatter that reference it, query it through the API and pull it into your SIEM over TAXII.

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Source: NIST National Vulnerability Database (record CVE-2018-20749), CISA KEV, FIRST EPSS (scores of 2026-10-06). This page is refreshed as NVD updates the record.