High severity · published Oct 8, 2026
CVE-2026-107615
DLL search order hijacking via screenhooks libraries in TightVNC Server
7.8
CVSS
0.1%
EPSS
No
On KEV
Description
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).
CVSS vector
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Attack vector
Local
Complexity
Low
Privileges
Low
User interaction
None
Confidentiality
High
Integrity
High
Availability
High
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.1% · higher than 3% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
TI
TightVNC · GlavSoft
before 2.8.88 · source: vendor
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-107615
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-107615
issue-tracking
https://sourceforge.net/p/vnc-tight/bugs/1666/
release-notes
https://www.tightvnc.com/whatsnew.php
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