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Fencer Intel
high 8.1

CVE-2018-6307 in the critical feed json

LibVNC before commit ca2a5ac02fbbadd0a21fabba779c1ea69173d10b contains heap use-after-free vulnerability in server code of file transfer ex…

published 2018-12-19 7 y ago modified 2026-06-17 4 mo ago also EUVD-2018-18068

cvss
8.1
version 3.0, NVD
cisa kev
Not listed
not in CISA's catalog
epss
26.5%
EPSS 26.5% chance of exploitation in 30 days, percentile 98%
public exploits
0
none known

Summary

LibVNC before commit ca2a5ac02fbbadd0a21fabba779c1ea69173d10b contains heap use-after-free vulnerability in server code of file transfer extension that can result remote code execution.

Patch / fix

  • libvnc_project libvncserver 0.9.12
  • libvncserver Debian 14, Debian 13, Debian 12 0.9.11+dfsg-1.2

debian advisories DEBIAN-CVE-2018-6307

  • libvncserver Ubuntu 14.04 LTS 0.9.9+dfsg-1ubuntu1.4
  • libvncserver Ubuntu 16.04 LTS 0.9.10+dfsg-3ubuntu0.16.04.3
  • libvncserver Ubuntu 18.04 LTS 0.9.11+dfsg-1ubuntu1.1

ubuntu advisories UBUNTU-CVE-2018-6307

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • LibVNCServer SLES 12 SP4, SLES 12 SP3, SLES 12 SP2-BCL +11 more 0.9.9-17.8.1
  • LibVNCServer SLE Workstation Extension 15, SLE Module for Package Hub 15 0.9.10-4.3.1
  • LibVNCServer SLES for SAP 11 SP4, SLES 11 SP4, SLES 11 SP3-TERADATA +3 more 0.9.1-160.6.1

suse advisories SUSE-SU-2019:0060-2SUSE-SU-2019:0080-1SUSE-SU-2019:13927-1SUSE-SU-2019:0060-1

  • LibVNCServer openSUSE Leap 15.0 0.9.10-lp150.3.3.1

opensuse advisories openSUSE-SU-2019:0053-1

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2018-6307 updated cvss 7.5

libvncserver: Use-after-free in file transfer extension server code allows for potential code execution

  • Red Hat Enterprise Linux 6 libvncserver Red Hat Enterprise Linux 7 libvncserver Red Hat Enterprise Linux 8 libvncserver
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

Exploit prediction

26.54% chance of exploitation in the next 30 days, higher than 98% of all scored CVEs (FIRST EPSS, 2026-11-09).

CVSS scores

assigned by version score vector
NVD 3.0 8.1 CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
NVD 2.0 6.8 AV:N/AC:M/Au:N/C:P/I:P/A:P

Affected products

  • n/a LibVNC

Classification

Weakness

References

Sources

Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.