Cross-Site Scripting (XSS) in WatchGuard Fireware OS (CVE-2026-13374, CVSS 4.8)

Summary

Cross-site scripting in WatchGuard Fireware OS (CVE-2026-13374). Risk of unauthorized operations or information disclosure.

Original description

The description as published by the source.

Improper Neutralization of Input During Web Page Generation (XSS or 'Cross-site Scripting') vulnerability in WatchGuard Fireware OS (ConnectWise Technology Integration module) allows Stored XSS. This vulnerability is an additional unmitigated attack path for CVE-2025-13937.

This issue affects Fireware OS 12.4 up to and including 12.12, 12.5 up to and including 12.5.18, and 2025.1 up to and including 2026.2.

Source: GitHub Security Advisories (Global) NVD GitHub Advisory

Auto-generated summary

Assembled by SecPulse from the source data (CVSS, CWE, affected versions) using templates — no AI involved. Check the original description and references below for exact details.

A vulnerability tracked as CVE-2026-13374 has been found in WatchGuard Fireware OS.
Risk of unauthorized operations or information disclosure. CVSS score: 4.8/10.
What to do: apply the vendor's official patched release.
If unsure, ask your IT team or search "WatchGuard Fireware OS CVE-2026-13374" on the vendor's site.

CVE-2026-13374 (WatchGuard Fireware OS) — CWE-79 / CVSS v3 4.8
Attack vector: remote (network-reachable)
Plan: 1) Audit SBOM/dependencies, 2) Stage→prod upgrade, 3) Add WAF/proxy monitoring on affected endpoints, 4) Hunt IOCs in logs.
Refs: see the GHSA / vendor advisory / patched release linked on this page.

❓ What is the problem

Cross-site scripting (XSS) (CWE-79) exists in WatchGuard Fireware OS.

📍 Affected scope

Check the vendor advisory for the affected versions of WatchGuard Fireware OS.

🔥 Severity

Severity: Medium (CVSS 4.8/10). Risk of unauthorized operations or information disclosure.

🔧 How to fix

Update to the patched release per vendor advisory.

🛡️ Workaround

Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.

🔍 Detection

Search webserver/proxy logs for unusual request patterns matching this CVE's known IOCs. Audit SBOM/dependencies to find affected services.

Response actions

Concrete steps and command examples for SOC/SRE teams to execute in order

1
Identify exposure identify
```
Audit SBOM/dependencies for affected components.
```
資産台帳・SBOM・依存マニフェストで WatchGuard Fireware OS を使っているサービスとバージョンを洗い出す。
2
Post-deployment verification verify
```
Confirm patched version is live in production
```
パッチ適用後、ステージングで PoC または同等の悪用パターンを再現して脆弱性が閉じたことを確認。本番ではアクセスログ・WAF でアラート再発が無いか継続監視。

Cross-Site Scripting (XSS) in WatchGuard Fireware OS (CVE-2026-13374)

Summary

Original description

Auto-generated summary

Response actions

References