NVD security advisory
Security advisory for Nagios XI
CVE-2026-119742
Full advisory details, affected packages, severity context, and original source.
Affected technology
Nagios XIPHP ecosystem
Advisory overview
Nagios XI before 2026R2 contains an OS command injection vulnerability in the MIB upload feature where the install_mib() function in mibs.php sanitizes uploaded filenames with an incomplete character-substitution filter that omits semicolons, pipes, and non-space IFS whitespace characters before passing them to a grep command run via exec(). An authenticated administrator can upload a MIB file with a crafted filename using tab characters to bypass the deny-list and pipe to sh via a multipart POST request to mibs.php, resulting in arbitrary OS command execution as the web server user.