# CVE-2026-18105: Fireware OS Uncontrolled Resource Consumption in Diagnostic Tasks Allows Denial of Service

> A low-privileged authenticated user can cause a denial of service of diagnostic tools by repeatedly starting and aborting crafted tasks in WatchGuard Fireware OS.

- **Severity:** High 7.1 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 29 Sep 2026
- **Updated:** 30 Sep 2026
- **Also known as:** GHSA-m7q5-h972-5236

## What is CVE-2026-18105?

CVE-2026-18105 is a high-severity denial of service vulnerability in Watchguard Fireware, published on 29 Sep 2026. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

An uncontrolled resource consumption vulnerability in Fireware OS's diagnostic tasks feature allows a low-privileged, authenticated user to cause a denial of service of the system's diagnostic tools by repeatedly starting and aborting a specially crafted diagnostic task through the web UI.

Weakness: CWE-770 (Allocation of Resources Without Limits or Throttling), CWE-400 (Uncontrolled Resource Consumption)

## Which versions are affected by CVE-2026-18105?

It affects 1 product.


Products: Watchguard Fireware.

## How do I fix CVE-2026-18105?

No fix has been published for CVE-2026-18105 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-18105 being exploited?

There is no known exploitation of CVE-2026-18105 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-2026-18105 and fix it if it is affected.

What it is: CVE-2026-18105 is a high-severity denial of service vulnerability in Watchguard Fireware, published on 29 Sep 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-18105 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-2026-18105/ (Markdown: https://insights.sbomify.com/CVE-2026-18105/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-18105
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-18105
- OSV: https://osv.dev/vulnerability/CVE-2026-18105

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-18105/
Summaries are generated and may contain mistakes; the official description above is the record.