Read the docs
TI-2019-11774 Aliases CVE-2019-15690GHSA-rx9w-c6jv-2grg

Heap-based buffer overflow in LibVNCServer

Priority MEDIUM 41CWE-122Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
Required
Attack complexity
Low
Impact type
Code execution
Confidentiality · integrity · availability
High · High · High
Fix status
Partial Red Hat: 9 fixed, 1 without a fix

Attack profile from CVSS 3.1 · CNA. Fix status from CNA and Red Hat. Impact type from CWE-122 and the CVSS impact.

Summary

LibVNCServer 0.9.12 release and earlier contains heap buffer overflow vulnerability within the HandleCursorShape() function in libvncclient/cursor.c. An attacker sends cursor shapes with specially crafted dimensions, which can result in remote code execution.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00768 55th percentileScored 2026-11-07
Fix Partial Red Hat: 3 advisoriesRed Hat: 9 fixed, 1 without a fix

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
No
Technical impact
Total

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
LibVNCLibVNCServerup to 0.9.12—No fix listedCNA
  • LibVNCServer VendorLibVNC Affected up to 0.9.12 Fixed in — No fix listed CNA

Remediation

Red Hat 3 advisories

  • RHSA-2020:0913 Released 2020-03-23 · Red Hat rating Important
    libvncserver security update
    • Red Hat Enterprise Linux Client (v. 7) libvncserver-0.9.9-14.el7_7
    • Red Hat Enterprise Linux Client Optional (v. 7) libvncserver-devel-0.9.9-14.el7_7
    • Red Hat Enterprise Linux Server (v. 7) libvncserver-0.9.9-14.el7_7
    • Red Hat Enterprise Linux Server Optional (v. 7) libvncserver-devel-0.9.9-14.el7_7
    • Red Hat Enterprise Linux Workstation (v. 7) libvncserver-0.9.9-14.el7_7
    • Red Hat Enterprise Linux Workstation Optional (v. 7) libvncserver-devel-0.9.9-14.el7_7
  • RHSA-2020:0920 Released 2020-03-23 · Red Hat rating Important
    libvncserver security update
    • Red Hat CodeReady Linux Builder (v. 8) libvncserver-0.9.11-9.el8_1.2, libvncserver-devel-0.9.11-9.el8_1.2
    • Red Hat Enterprise Linux AppStream (v. 8) libvncserver-0.9.11-9.el8_1.2
  • RHSA-2020:0921 Released 2020-03-23 · Red Hat rating Important
    libvncserver security update
    • Red Hat Enterprise Linux AppStream E4S (v. 8.0) libvncserver-0.9.11-9.el8_0.2

Vendor assessments

Red Hat

Red Hat rating: Important. Red Hat's page for this CVE →

ProductStatusPlan or fix
Red Hat Enterprise Linux 6AffectedNo fix planned: Out of support scope
Red Hat CodeReady Linux Builder (v. 8)Fixed RHSA-2020:0920
Red Hat Enterprise Linux AppStream (v. 8)Fixed RHSA-2020:0920
Red Hat Enterprise Linux AppStream E4S (v. 8.0)Fixed RHSA-2020:0921
Red Hat Enterprise Linux Client (v. 7)Fixed RHSA-2020:0913
Red Hat Enterprise Linux Client Optional (v. 7)Fixed RHSA-2020:0913
Red Hat Enterprise Linux Server (v. 7)Fixed RHSA-2020:0913
Red Hat Enterprise Linux Server Optional (v. 7)Fixed RHSA-2020:0913
Red Hat Enterprise Linux Workstation (v. 7)Fixed RHSA-2020:0913
Red Hat Enterprise Linux Workstation Optional (v. 7)Fixed RHSA-2020:0913

Timeline

  1. 2026-10-02 Threatist record created from CVE-2019-15690
  2. 2026-10-03 Alias added: GHSA-rx9w-c6jv-2grg

References

Advisory 1

  • TI-2026-37265 libvncclient Tight decoder has an attacker-controlled heap out-of-bounds write CVSS 3.1HIGH 8.8
  • TI-2026-32847 LibVNCClient Tight Gradient decoding allows malicious server-triggered heap/stack OOB writes CVSS 3.1HIGH 8.8

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences