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

> A local attacker can execute arbitrary code with SYSTEM privileges by planting a malicious DLL in a writable directory due to unsafe DLL loading in TightVNC Server.

- **Severity:** High 7.8 (`CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 8 Oct 2026
- **Updated:** 8 Oct 2026
- **Also known as:** GHSA-c7v7-v5cv-43wm

## What is CVE-2026-107615?

CVE-2026-107615 is a high-severity vulnerability in GlavSoft TightVNC, published on 8 Oct 2026. It can only be exploited from the same machine or local network, with no action from the victim.

### 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).

Weakness: CWE-427 (Uncontrolled Search Path Element)

## Which versions are affected by CVE-2026-107615?


## How do I fix CVE-2026-107615?

No fix has been published for CVE-2026-107615 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-107615 being exploited?

There is no known exploitation of CVE-2026-107615 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-107615 and fix it if it is affected.

What it is: CVE-2026-107615 is a high-severity vulnerability in GlavSoft TightVNC, published on 8 Oct 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-107615 in the wild and no public exploit code.

Affected product: GlavSoft TightVNC. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-107615/ (Markdown: https://insights.sbomify.com/CVE-2026-107615/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-107615
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-107615
- OSV: https://osv.dev/vulnerability/CVE-2026-107615

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-107615/
Summaries are generated and may contain mistakes; the official description above is the record.