---
id: CVE-2026-107613
title: >-
  A NULL pointer dereference vulnerability in the Win8ScreenDriver component of
  GlavSoft TightVNC Server for Windows before 2.8.88 allows an attacker to crash
  the server, causing a denial of service
summary: >-
  A NULL pointer dereference vulnerability in the Win8ScreenDriver component of
  GlavSoft TightVNC Server for Windows before 2.8.88 allows an attacker to crash
  the server, causing a denial of service. When re-initialization of the DXGI
  Desk…
severity: medium
cvss: 5.9
cvssVector: 'CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H'
cwe:
  - CWE-476
vendor: GlavSoft
product: TightVNC
affected:
  - TightVNC < 2.8.88
published: '2026-10-08'
updated: '2026-10-08'
sourceUpdated: '2026-10-08T21:10:00.133'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-107613'
references:
  - url: 'https://sourceforge.net/p/vnc-tight/bugs/1660/'
    label: 33c584b5-0579-4c06-b2a0-8d8329fcab9c
  - url: 'https://www.tightvnc.com/whatsnew.php'
    label: 33c584b5-0579-4c06-b2a0-8d8329fcab9c
tags:
  - nvd
  - cve.org
ssvc:
  exploitation: none
  automatable: 'no'
  technicalImpact: partial
  timestamp: '2026-10-08T14:01:21.134363Z'
ingestedAt: '2026-10-08T14:47:16.341Z'
---

## Overview

A NULL pointer dereference vulnerability in the Win8ScreenDriver component of GlavSoft TightVNC Server for Windows before 2.8.88 allows an attacker to crash the server, causing a denial of service. When re-initialization of the DXGI Desktop Duplication driver fails in applyNewScreenProperties() (for example after a GPU reset, display hot-plug or session change), m_drvImpl is left NULL and is subsequently dereferenced without a check by executeDetection(), getScreenBuffer(), grabFb(), getScreenPropertiesChanged() and getCursorPosition().

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.