An integer underflow in WinCursorShapeUtils::trimTransparent() in GlavSoft TightVNC Server for Windows before 2.8.88 allows a local authenticated user to crash the server, and potentially read out-of-bounds memory, by causing a cursor shape with a width or height of zero to be processed on the DXGI capture path. The loop bound width - 1 wraps to 0xFFFFFFFF, producing an access roughly 4 GB beyond the 64 KB cursor buffer; a monochrome cursor of height 1 also becomes 0 because getCursorHeight() halves the height in place.
History

Fri, 09 Oct 2026 09:15:00 +0000

Type Values Removed Values Added
First Time appeared Glavsoft
Glavsoft tightvnc
Vendors & Products Glavsoft
Glavsoft tightvnc

Thu, 08 Oct 2026 15:15:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}


Thu, 08 Oct 2026 14:00:00 +0000

Type Values Removed Values Added
Description An integer underflow in WinCursorShapeUtils::trimTransparent() in GlavSoft TightVNC Server for Windows before 2.8.88 allows a local authenticated user to crash the server, and potentially read out-of-bounds memory, by causing a cursor shape with a width or height of zero to be processed on the DXGI capture path. The loop bound width - 1 wraps to 0xFFFFFFFF, producing an access roughly 4 GB beyond the 64 KB cursor buffer; a monochrome cursor of height 1 also becomes 0 because getCursorHeight() halves the height in place.
Title Integer underflow in TightVNC Server cursor shape trimming leads to out-of-bounds read
Weaknesses CWE-125
CWE-191
References
Metrics cvssV3_1

{'score': 6.1, 'vector': 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:H'}


cve-icon MITRE

Status: PUBLISHED

Assigner: securin

Published: 2026-10-08T13:39:58.297Z

Updated: 2026-10-08T14:01:01.624Z

Reserved: 2026-10-08T13:23:07.677Z

Link: CVE-2026-107614

cve-icon Vulnrichment

Updated: 2026-10-08T14:00:55.983Z

cve-icon NVD

Status : Awaiting Analysis

Published: 2026-10-08T14:16:50.163

Modified: 2026-10-08T21:10:00.133

Link: CVE-2026-107614

cve-icon Redhat

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