CVE-2026-119742: Nagios XI · OS Command Injection
Affects Nagios XISource CVE Database V5
Not known to be exploited · CVSS 8.6 High : upgrade to 2026R2 soon.
Data as of 3 Nov 2026, 16:28 UTC
Thin evidence
One scorer or none| CNA (VulnCheck) | CVSS 4.0 | 8.6 |
|---|---|---|
| CNA (VulnCheck) | CVSS 3.1 | 7.2 |
- Patch
- Available – fixed in 2026R2
CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:NExploitation evidence
Disclosed: evidence found.
CVE published 3 Nov 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 3 Nov 2026.
What to do
Upgrade Nagios XI to 2026R2.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| Nagios Enterprises, LLCNagios XI | Affected
| Fixed in
|
AI-suggested
Upgrade Nagios XI to version 2026R2 or later, where this vulnerability is fixed. Since an official fix is available, applying this update is the recommended remediation. No additional mitigations are specified by the vendor advisory.
Description
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.