# CVE-2026-8247: WatchGuard Firebox admd Out of Bounds Write Vulnerability

> An unauthenticated attacker on the local network can execute arbitrary code via an out-of-bounds write in WatchGuard Firebox admd.

- **Severity:** High 7.7 (`CVSS:4.0/AV:A/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 2 Jul 2026
- **Updated:** 27 Aug 2026
- **Also known as:** GHSA-h2w9-p676-66ch

## What is CVE-2026-8247?

CVE-2026-8247 is a high-severity memory corruption vulnerability in Watchguard Fireware, published on 2 Jul 2026. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

An Out-of-bounds Write vulnerability in WatchGuard Fireware OS may allow an unauthenticated attacker on the same local network segment to execute arbitrary code.

This vulnerability affects Fireware OS 11.0 up to and including 11.12.4_Update1, 12.0 up to and including 12.12 and 2025.1 up to and including 2026.2.

Weakness: CWE-787 (Out-of-bounds Write), CWE-120 (Buffer Copy without Checking Size of Input)

## Which versions are affected by CVE-2026-8247?

It affects 1 product.


Products: Watchguard Fireware.

## How do I fix CVE-2026-8247?

No fix has been published for CVE-2026-8247 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-8247 being exploited?

There is no known exploitation of CVE-2026-8247 in the wild and no public exploit code.

## Other vulnerabilities in Watchguard Fireware

- [CVE-2022-26318](https://insights.sbomify.com/CVE-2022-26318/): WatchGuard Firebox and XTM Appliances Arbitrary Code Execution (critical 9.8, exploited in the wild)
- [CVE-2025-14733](https://insights.sbomify.com/CVE-2025-14733/): WatchGuard Firebox Out of Bounds Write (critical 9.3, exploited in the wild)
- [CVE-2025-9242](https://insights.sbomify.com/CVE-2025-9242/): WatchGuard Firebox Out-of-Bounds Write (critical 9.3, exploited in the wild)
- [CVE-2022-23176](https://insights.sbomify.com/CVE-2022-23176/): WatchGuard Firebox and XTM Privilege Escalation (high 8.8, exploited in the wild)
- [CVE-2022-31789](https://insights.sbomify.com/CVE-2022-31789/): Integer overflow in n/a (critical 9.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-8247 and fix it if it is affected.

What it is: CVE-2026-8247 is a high-severity memory corruption vulnerability in Watchguard Fireware, published on 2 Jul 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-2026-8247 in the wild and no public exploit code.

Affected product: Watchguard Fireware. 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-2026-8247/ (Markdown: https://insights.sbomify.com/CVE-2026-8247/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-8247
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-8247
- OSV: https://osv.dev/vulnerability/CVE-2026-8247

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-8247/
Summaries are generated and may contain mistakes; the official description above is the record.