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TI-2026-69582 Aliases CVE-2026-107615GHSA-c7v7-v5cv-43wm

DLL search order hijacking via screenhooks libraries in TightVNC Server

Priority LOW 35CWE-427Published · Updated

Key facts

Attack vector
Local
Privileges required
Low
User interaction
None
Attack complexity
Low
Impact type
Code execution
Confidentiality · integrity · availability
High · High · High
Fix status
Fixed

Attack profile from CVSS 3.1 · CNA. Fix status from CNA. Impact type from CWE-427.

Summary

GlavSoft TightVNC Server for Windows before 2.8.88 has an uncontrolled search path element flaw (CWE-427). The service loads screenhooks32.dll and screenhooks64.dll by bare file name without restricting the DLL search path, so it can load a planted DLL from a writable directory earlier in the search order. A local authenticated user can use this to execute arbitrary code with SYSTEM privileges.

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

Description from the CNA

An uncontrolled search path element vulnerability in GlavSoft TightVNC Server for Windows before 2.8.88 allows a local authenticated user to execute arbitrary code with SYSTEM privileges. DynamicLibrary::init() (and ThemeLib) load screenhooks32.dll / screenhooks64.dll with LoadLibrary() using a bare file name and no LOAD_LIBRARY_SEARCH_* flags, so the TightVNC service follows the default DLL search order and loads an attacker-planted DLL from a writable directory earlier in that order (for example, an installation directory with permissive ACLs).

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.0014 3rd 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
Total

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

Update TightVNC Server for Windows to version 2.8.88, the fixed version.

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-2026-69579 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
    • TI-2026-69581 Integer underflow in TightVNC Server cursor shape trimmingPriority LOW 26
    Show all 5 records →

Timeline

  1. 2026-10-08 Threatist record created from CVE-2026-107615
  2. 2026-10-08 Alias added: GHSA-c7v7-v5cv-43wm

References

Patch 1

Other 1

  • 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
  • TI-2026-69580 NULL pointer dereference in TightVNC Server Win8ScreenDriver crashes server CVSS 3.1MEDIUM 5.9

Sources

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