# CVE-2026-107613: NULL pointer dereference in TightVNC Server Win8ScreenDriver after failed DXGI re-initialization

> An attacker can crash the TightVNC Server by triggering a null pointer dereference during DXGI re-initialization failures, causing denial of service.

- **Severity:** Medium 5.9 (`CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 8 Oct 2026
- **Updated:** 8 Oct 2026
- **Also known as:** GHSA-c4jj-c6x2-r973

## What is CVE-2026-107613?

CVE-2026-107613 is a medium-severity vulnerability in GlavSoft TightVNC, published on 8 Oct 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

A NULL pointer dereference vulnerability in the Win8ScreenDriver component of GlavSoft TightVNC Server for Windows before 2.8.88 allows an attacker to crash the server, causing a denial of service. When re-initialization of the DXGI Desktop Duplication driver fails in applyNewScreenProperties() (for example after a GPU reset, display hot-plug or session change), m_drvImpl is left NULL and is subsequently dereferenced without a check by executeDetection(), getScreenBuffer(), grabFb(), getScreenPropertiesChanged() and getCursorPosition().

Weakness: CWE-476 (NULL Pointer Dereference)

## Which versions are affected by CVE-2026-107613?


## How do I fix CVE-2026-107613?

No fix has been published for CVE-2026-107613 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-107613 being exploited?

There is no known exploitation of CVE-2026-107613 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-107613 and fix it if it is affected.

What it is: CVE-2026-107613 is a medium-severity vulnerability in GlavSoft TightVNC, published on 8 Oct 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-107613 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-2026-107613/ (Markdown: https://insights.sbomify.com/CVE-2026-107613/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-107613
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-107613
- OSV: https://osv.dev/vulnerability/CVE-2026-107613

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-107613/
Summaries are generated and may contain mistakes; the official description above is the record.