Heap-based buffer overflow in LibVNCServer - CVE-2026-50538

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Main Vulnerability Database Vulnerabilities #VU132966

Heap-based buffer overflow in LibVNCServer - CVE-2026-50538

Published: May 29, 2026 / Updated: August 24, 2026


Vulnerability identifier: #VU132966
CSH Severity: High
CVSS v4: 8.6 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-50538
CWE-ID: CWE-122
Exploitation vector: Remote access
Exploit availability: No public exploit available

Vulnerability details

The vulnerability allows a remote attacker to execute arbitrary code on the target system.

The vulnerability exists due to a boundary error in libvncclient Tight decoder. A remote attacker can pass specially crafted data to the application, trigger a heap-based buffer overflow and execute arbitrary code on the target system.

Successful exploitation of this vulnerability may result in complete compromise of vulnerable system.


Affected software

LibVNCServer
SUSE Linux Enterprise Server 12 SP5 LTSS Extended
SUSE Linux Enterprise Server 12 SP5
SUSE Linux Enterprise Server for SAP Applications 12
SUSE Linux Enterprise High Performance Computing 12
SUSE Linux Enterprise Server 12
SUSE Linux Enterprise Real Time 15
SUSE Linux Enterprise Server 15
SUSE Linux Enterprise Server for SAP Applications 15
SUSE Linux Enterprise Desktop 15
SUSE Linux Enterprise Workstation Extension 15
SUSE Package Hub 15
openSUSE Leap
openEuler
Ubuntu
libvncclient0-debuginfo
libvncserver0-debuginfo
libvncclient0
libvncserver0
LibVNCServer-debugsource
LibVNCServer-devel
libvncserver (Ubuntu package)
libvncserver-debuginfo
libvncserver-debugsource
libvncserver-devel
libvncserver
libvncserver1-debuginfo
libvncserver1
libvncclient1-debuginfo
libvncclient1

How to mitigate CVE-2026-50538

Cybersecurity Help is currently unaware of any official solution to address this vulnerability.

libvncclient0-debuginfo - update to 0.9.9-17.50.1
libvncserver0-debuginfo - addressed in versions 0.9.9-17.50.1, 0.9.10-150000.4.41.1
libvncclient0 - update to 0.9.9-17.50.1
libvncserver0 - addressed in versions 0.9.9-17.50.1, 0.9.10-150000.4.41.1
LibVNCServer-debugsource - addressed in versions 0.9.9-17.50.1, 0.9.10-150000.4.41.1, 0.9.14-150600.3.12.1
LibVNCServer-devel - addressed in versions 0.9.9-17.50.1, 0.9.14-150600.3.12.1
libvncserver (Ubuntu package) - addressed in versions 0.9.13+dfsg-3ubuntu0.2, 0.9.14+dfsg-1ubuntu0.2, 0.9.15+dfsg-1ubuntu0.2, 0.9.15+dfsg-3ubuntu0.2
libvncserver-debuginfo - update to 0.9.13-6
libvncserver-debugsource - update to 0.9.13-6
libvncserver-devel - update to 0.9.13-6
libvncserver - update to 0.9.13-6
libvncserver1-debuginfo - update to 0.9.14-150600.3.12.1
libvncserver1 - update to 0.9.14-150600.3.12.1
libvncclient1-debuginfo - update to 0.9.14-150600.3.12.1
libvncclient1 - update to 0.9.14-150600.3.12.1

External References

Related Security Bulletins