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TI-2026-69580 Aliases CVE-2026-107613GHSA-c4jj-c6x2-r973

NULL pointer dereference in TightVNC Server Win8ScreenDriver crashes server

Priority LOW 26CWE-476Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
None
Attack complexity
High
Impact type
Denial of service
Confidentiality · integrity · availability
None · None · High
Fix status
Fixed

Attack profile from CVSS 3.1 · CNA. Fix status from CNA. Impact type from CWE-476.

Summary

GlavSoft TightVNC Server for Windows before 2.8.88 contains a NULL pointer dereference (CWE-476) in its Win8ScreenDriver component. When re-initialization of the DXGI Desktop Duplication driver fails in applyNewScreenProperties(), such as after a GPU reset, display hot-plug or session change, the driver implementation pointer is left NULL and is dereferenced without a check. An unauthenticated remote attacker can crash the server, causing a denial of service, under high attack complexity.

Written with Claude Haiku 5.5 from the sources below · 2026-10-29

Description from the CNA

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().

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00308 23rd percentileScored 2026-11-07
Fix Fixed TightVNC (GlavSoft): 2.8.88

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
No
Technical impact
Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
GlavSoftTightVNCbefore 2.8.882.8.88Patch availableCNA
  • TightVNC VendorGlavSoft Affected before 2.8.88 Fixed in 2.8.88 Patch available CNA

Remediation

Upgrade GlavSoft TightVNC Server to version 2.8.88 or later, which fixes the flaw.

Written with Claude Haiku 5.5 from the sources below · 2026-10-29

  • Fix · CNA TightVNC (GlavSoft) Fixed in 2.8.88

Fixed in the same release

Records fixed by the same vendor advisory or release, as the CNA lists them.

  • Release ·

    GlavSoft TightVNC 2.8.88

    5 records Highest priority Priority LOW 5 LOW

    Other records, highest priority first

    • TI-2026-69582 DLL search order hijacking via screenhooks libraries in TightVNC ServerPriority LOW 35
    • TI-2026-69579 Incorrect permissions on TightVNC IPC shared memory in TightVNC ServerPriority LOW 35
    • TI-2026-69578 Out-of-bounds read in TightVNC Viewer ZRLE palette decodingPriority LOW 31
    Show all 5 records →

Timeline

  1. 2026-10-08 Threatist record created from CVE-2026-107613
  2. 2026-10-08 Alias added: GHSA-c4jj-c6x2-r973

References

Patch 1

Other 1

  • TI-2026-69582 DLL search order hijacking via screenhooks libraries in TightVNC Server CVSS 3.1HIGH 7.8
  • TI-2026-69579 Incorrect permissions on TightVNC IPC shared memory in TightVNC Server CVSS 3.1HIGH 7.8
  • TI-2026-69578 Out-of-bounds read in TightVNC Viewer ZRLE palette decoding CVSS 3.1HIGH 7.1
  • TI-2026-69581 Integer underflow in TightVNC Server cursor shape trimming CVSS 3.1MEDIUM 6.1

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences