LibVNCServer versions 0.9.15 and prior (fixed in commit 009008e) contain a heap out-of-bounds read vulnerability in the UltraZip encoding handler that allows a malicious VNC server to cause information disclosure or application crash. Attackers can exploit improper bounds checking in the HandleUltraZipBPP() function by manipulating subrectangle header counts to read beyond the allocated heap buffer.
History

Wed, 25 Mar 2026 21:00:00 +0000

Type Values Removed Values Added
First Time appeared Libvncserver Project
Libvncserver Project libvncserver
CPEs cpe:2.3:a:libvncserver_project:libvncserver:*:*:*:*:*:*:*:*
Vendors & Products Libvncserver Project
Libvncserver Project libvncserver
Metrics cvssV3_1

{'score': 5.4, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:L'}

cvssV3_1

{'score': 8.1, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:H'}


Wed, 25 Mar 2026 14:15:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'poc', 'Technical Impact': 'partial'}, 'version': '2.0.3'}


Wed, 25 Mar 2026 12:00:00 +0000

Type Values Removed Values Added
First Time appeared Libvncserver
Libvncserver libvncserver
Vendors & Products Libvncserver
Libvncserver libvncserver

Wed, 25 Mar 2026 00:15:00 +0000

Type Values Removed Values Added
References
Metrics threat_severity

None

cvssV3_1

{'score': 5.4, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:L'}

threat_severity

Moderate


Tue, 24 Mar 2026 17:45:00 +0000

Type Values Removed Values Added
Description LibVNCServer versions 0.9.15 and prior (fixed in commit 009008e) contain a heap out-of-bounds read vulnerability in the UltraZip encoding handler that allows a malicious VNC server to cause information disclosure or application crash. Attackers can exploit improper bounds checking in the HandleUltraZipBPP() function by manipulating subrectangle header counts to read beyond the allocated heap buffer.
Title LibVNCServer UltraZip Encoding Heap Out-of-bounds Read
Weaknesses CWE-125
References
Metrics cvssV4_0

{'score': 6.9, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:L/SC:N/SI:N/SA:N'}


cve-icon MITRE

Status: PUBLISHED

Assigner: VulnCheck

Published:

Updated: 2026-03-25T13:41:15.171Z

Reserved: 2026-03-16T18:11:41.759Z

Link: CVE-2026-32853

cve-icon Vulnrichment

Updated: 2026-03-25T13:41:06.842Z

cve-icon NVD

Status : Analyzed

Published: 2026-03-24T18:16:09.253

Modified: 2026-03-25T20:48:30.733

Link: CVE-2026-32853

cve-icon Redhat

Severity : Moderate

Publid Date: 2026-03-24T17:30:40Z

Links: CVE-2026-32853 - Bugzilla