Vulnerability · Published Oct 8, 2026 · Assigned by securin

CVE-2026-107615DLL search order hijacking via screenhooks libraries in TightVNC Server

High 7.8

In plain English

A high-severity uncontrolled search path in TightVNC from GlavSoft. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.1% (higher than 3% of all known vulnerabilities).

Severity (CVSS 3.1)7.8High

Exploit odds (30 days)0.1%top 96.6% of all CVEs

Exploited in the wildNo reportsCISA SSVC: none

Attack toolingNoneno public tooling known

Official 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).

Affected packages & fixed versions

Ecosystem	Package	Fixed in	Advisory
Ubuntu:22.04:LTS	tightvnc	no fix listed	UBUNTU-CVE-2026-107615
Ubuntu:24.04:LTS	tightvnc	no fix listed	UBUNTU-CVE-2026-107615
Ubuntu:26.04:LTS	tightvnc	no fix listed	UBUNTU-CVE-2026-107615

Affected products (as reported)

Vendor	Product	Versions
GlavSoft	TightVNC	0 – before 2.8.88

Weakness: CWE-427 · Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

References

TightVNC bug #1666 issue-tracking
TightVNC release notes (2.8.88) release-notes, patch