# CVE-2026-84854: Out of Bound Write on WibuKey for Windows

> A local attacker can trigger an out-of-bounds write in the WibuKey Windows driver, causing a system crash or potential kernel memory modification.

- **Severity:** High 7.0 (`CVSS:3.1/AV:L/AC:H/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:** 6 Oct 2026
- **Updated:** 15 Oct 2026
- **Also known as:** GHSA-pc55-w49m-q7wf

## What is CVE-2026-84854?

CVE-2026-84854 is a high-severity memory corruption vulnerability in wibu-systems-ag wibukey, published on 6 Oct 2026. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

In the WibuKey driver for Windows below Version 6.72, insufficient validation of user input when calculating the size of a kernel buffer could cause small amounts of data to be written outside the intended kernel buffer. This can lead to a system crash. Under unfavorable circumstances, adjacent kernel memory may be modified.

Weakness: CWE-787 (Out-of-bounds Write)

## Which versions are affected by CVE-2026-84854?


## How do I fix CVE-2026-84854?

No fix has been published for CVE-2026-84854 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-84854 being exploited?

There is no known exploitation of CVE-2026-84854 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-84854 and fix it if it is affected.

What it is: CVE-2026-84854 is a high-severity memory corruption vulnerability in wibu-systems-ag wibukey, published on 6 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-2026-84854 in the wild and no public exploit code.

Affected product: wibu-systems-ag wibukey. 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-2026-84854/ (Markdown: https://insights.sbomify.com/CVE-2026-84854/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-84854
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-84854
- OSV: https://osv.dev/vulnerability/CVE-2026-84854

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From sbomify Insights: https://insights.sbomify.com/CVE-2026-84854/
Summaries are generated and may contain mistakes; the official description above is the record.