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UK Cyber Defence
VulnerabilityAwaiting Analysis

CVE-2026-107614

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…

MEDIUM 6.1EPSS 0.11%

Does this matter?

Lower severity and a low EPSS score (0.11%). Track it; it rarely justifies an emergency change on its own.

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.

CVSS 3.1
6.1 MEDIUMCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:H
EPSS
0.11% probability · 1th percentile
Public exploits
None in Exploit-DB
CISA KEV
Not listed
Weakness
CWE-125, CWE-191
Source
33c584b5-0579-4c06-b2a0-8d8329fcab9c
EPSS trend
0%3%5%9 October 2026: 0.10%26 October 2026: 0.11%9 October 202626 October 2026

EPSS moved from 0.1% on 9 October 2026 to 0.1% on 26 October 2026.

Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.