Unsafe Deserialization in Watchguard Fireware (CVE-2026-13371, CVSS 4.9)

Summary

Vulnerability in Watchguard Fireware (CVE-2026-13371). Risk of unauthorized operations or information disclosure.

Original description

The description as published by the source.

An authenticated administrator can trigger a denial-of-service condition in the Fireware Management Web UI by sending malformed or crafted data to the put_data endpoint, which performs unsafe deserialization of the attacker-supplied input.

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-2026-13371 has been found in Watchguard Fireware.
Risk of unauthorized operations or information disclosure. CVSS score: 4.9/10.
What to do: apply the vendor's official patched release.
If unsure, ask your IT team or search "Watchguard Fireware CVE-2026-13371" on the vendor's site.

CVE-2026-13371 (Watchguard Fireware) — CWE-502 / CVSS v3 4.9
Attack vector: remote (network-reachable) / no user interaction
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

Unsafe deserialization (CWE-502) exists in Watchguard Fireware.

📍 Affected scope

Check the vendor advisory for the affected versions of Watchguard Fireware.

🔥 Severity

Severity: Medium (CVSS 4.9/10). 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. Run grep -r 'Fireware' . against your dependency files (package-lock.json, requirements.txt, go.sum) to find affected services.

Response actions

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

1
Identify exposure identify
```
grep -r 'Fireware' . | grep -v node_modules
```
リポジトリと本番環境の依存ファイル (package-lock.json / requirements.txt / go.sum / Gemfile.lock 等) で Fireware を grep し、稼働しているサービス・バージョンを把握する。
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。

Unsafe Deserialization in Watchguard Fireware (CVE-2026-13371)

Summary

Original description

Auto-generated summary

Response actions

References