Vulnerability in nagios4 (DEBIAN-CVE-2026-48550)

Summary

Vulnerability in nagios4 (DEBIAN-CVE-2026-48550). Risk of unauthorized operations or information disclosure. Mitigation: upgrade to 4.4.6-4+deb12u2 or later.

Original description

The description as published by the source.

Nagios Core before 4.5.14 and Nagios XI before 2026R1.7 are vulnerable to reflected cross-site scripting in cmd.cgi via the NagFormId parameter. An unauthenticated remote attacker can craft a malicious link that, when followed by an authenticated user, executes arbitrary JavaScript in the victim's browser.

Source: OSV.dev (Open Source Vulnerabilities) OSV

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 DEBIAN-CVE-2026-48550 has been found in nagios4.
Risk of unauthorized operations or information disclosure.
What to do: upgrade nagios4 to 4.4.6-4+deb12u2 or later.
If unsure, ask your IT team or search "nagios4 DEBIAN-CVE-2026-48550" on the vendor's site.

DEBIAN-CVE-2026-48550 (nagios4)
Patched: 4.4.6-4+deb12u2 — apply immediately
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

A vulnerability (unclassified) exists in nagios4.

📍 Affected scope

Check the vendor advisory for the affected versions of nagios4.

🔥 Severity

Severity: ?. Risk of unauthorized operations or information disclosure.

🔧 How to fix

Update to 4.4.6-4+deb12u2.

🛡️ 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 'nagios4' . 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 'nagios4' . | 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 nagios4 を grep し、稼働しているサービス・バージョンを把握する。
2
Apply patch patch
```
Upgrade nagios4 to 4.4.6-4+deb12u2
```
ステージング環境で 4.4.6-4+deb12u2 に上げて回帰テスト → 本番反映。回帰テストはアプリの主要ハッピーパスを含めること。
3
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。

Affected packages

Debian:12 nagios4

[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"4.4.6-4+deb12u2"}]}]

Debian:13 nagios4

[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"4.4.6-4.1+deb13u2"}]}]

Debian:14 nagios4

[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"4.5.14+ds-1"}]}]

References

advisory security-tracker.debian.org