CVE-2026-107615
DLL search order hijacking via screenhooks libraries in TightVNC Server
GlavSoft TightVNC
CVSS
7.8HighExploitationNo known exploitationNot in CISA KEV, which does not prove it is unexploitedCISA KEV
Exploit odds (EPSS)0.14%Chance of exploitation activity in the next 30 days, higher than 3% of CVEs. Scored 23 Oct 2026FIRST EPSS
What fixes it
- 2.8.88TightVNCCVE List
A fixed version on one release line is not the upgrade target for every line. Check your exact version and any vendor backports.
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).
Text from CVE List
Affected versions 1
- TightVNCaffected: all versions before 2.8.88CVE List