CVE-2020-36858 Nagios Log Server < 2.1.6 XSS via Create User, Edit User, & Manage Host Lists Pages

What is CVE-2020-36858?

CVE-2020-36858 is a medium-severity cross-site scripting vulnerability in Nagios Log Server, published on 30 Oct 2025. Any signed-in user can exploit it over the network, and only if a user opens a file or follows a link.

Official description

Nagios Log Server versions prior to 2.1.6 contain cross-site scripting (XSS) vulnerabilities via the web interface on the Create User, Edit User, and Manage Host Lists pages. Insufficient validation or escaping of user-supplied input may allow an attacker to inject and execute arbitrary script in the context of a victim's browser.

Weakness: CWE-79

Which versions are affected by CVE-2020-36858?

It affects 1 product.

Products include Nagios Log Server.

How do I fix CVE-2020-36858?

No fix has been published for CVE-2020-36858 yet. Limit exposure of the affected software until one is available.

Escape output for the context it lands in and set a strict Content Security Policy. Upgrading the affected component is the real fix. More about Cross-site scripting.

Is CVE-2020-36858 being exploited?

There is no known exploitation of CVE-2020-36858 in the wild and no public exploit code.

Other vulnerabilities in Nagios Log Server

• CVE-2025-44823 Information disclosure in Log Server Critical 9.9
• CVE-2025-34277 Nagios Log Server < 2024R1.3.1 RCE via Malformed Dashboard ID Critical 9.4
• CVE-2025-34274 Nagios Log Server < 2024R2.0.3 Logstash Process Root Privileges Critical 9.3
• CVE-2023-7322 Nagios Log Server < 2024R1 Incorrect Authorization Granting Full API Access High 8.7
• CVE-2025-34271 Nagios Log Server < 2024R2.0.2 Cluster Manager Credential Requests Sent Over Plaintext High 8.7

Sources

• CVE record
• NVD
• OSV
• GitHub advisory
• How this page is made

Also known as GHSA-wr48-wpx9-wpm2.