# CVE-2026-78617: WatchGuard Dimension Web UI Authentication Brute-Force Due to Missing Rate Limiting

> Remote attackers can brute-force user accounts on WatchGuard Dimension due to missing default rate limiting, requiring configuration changes to enable account lockout.

- **Severity:** Medium 6.3 (`CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 27 Aug 2026
- **Updated:** 28 Aug 2026
- **Also known as:** GHSA-3x89-jjqx-2x3q

## What is CVE-2026-78617?

CVE-2026-78617 is a medium-severity authentication bypass vulnerability in WatchGuard Dimension, published on 27 Aug 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

WatchGuard Dimension's web login endpoint does not enforce effective rate-limiting or account lockout by default allowing a remote attacker to perform automated password guessing against user accounts. If the account lockout setting is enabled, brute-force attempts are blocked after a defined number of failed attempts, but this setting is not enabled by default.

Weakness: CWE-307 (Improper Restriction of Excessive Authentication Attempts), CWE-203 (Observable Discrepancy)

## Which versions are affected by CVE-2026-78617?


## How do I fix CVE-2026-78617?

No fix has been published for CVE-2026-78617 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-78617 being exploited?

There is no known exploitation of CVE-2026-78617 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-78617 and fix it if it is affected.

What it is: CVE-2026-78617 is a medium-severity authentication bypass vulnerability in WatchGuard Dimension, published on 27 Aug 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-2026-78617 in the wild and no public exploit code.

Affected product: WatchGuard Dimension. 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-2026-78617/ (Markdown: https://insights.sbomify.com/CVE-2026-78617/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-78617
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-78617
- OSV: https://osv.dev/vulnerability/CVE-2026-78617

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-78617/
Summaries are generated and may contain mistakes; the official description above is the record.