What’s Vulnerable › Vulnerabilities

CVE-2023-7312: Nagios Fusion < 4.2.0 Email Settings Stored XSS via SMTP/sendmail

• Severity: medium (CVSS 4.8 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 1.0% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2025-10-30 · updated 2026-10-18
• Weakness: CWE-79

Description

Nagios Fusion versions prior to 4.2.0 contain a stored cross-site scripting (XSS) vulnerability when adding or configuring Email Settings. Unsanitized user input can be stored and later rendered in the administrative UI, causing JavaScript to execute in the browser of any user who views the affected page. An attacker who can add or modify SMTP/email settings or manipulate the sendmail configuration fields could persist a malicious payload that executes in the context of other users' browsers.

Affected products

• Nagios Fusion: before 4.2.0 — fixed in 4.2.0

How to fix

Upgrade to a fixed version: Nagios Fusion 4.2.0. Check the vendor advisory for mitigations.

References

• https://www.nagios.com/changelog/nagios-fusion/
• https://www.nagios.com/products/security/#fusion
• https://www.vulncheck.com/advisories/nagios-fusion-email-settings-stored-xss-via-smtp-sendmail

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