Nagios XI before 2026R2 contains an OS command injection vulnerability in the MIB upload feature where the
Source GCVE Database
Not known to be exploited · CVSS 8.6 High : upgrade to 2026R2 soon.
Data as of 3 Nov 2026, 16:42 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
If you cannot patch yet, restrict administrator access to trusted personnel only and monitor for suspicious activity related to MIB uploads. Avoid exposing the Nagios XI interface to untrusted networks.
Description
Nagios XI versions prior to 2026R2 have an OS command injection vulnerability in the MIB upload feature. The vulnerability arises because the install_mib() function in mibs.php inadequately sanitizes uploaded filenames, omitting certain characters like semicolons, pipes, and some whitespace characters. An authenticated administrator can exploit this by uploading a crafted MIB file with tab characters in the filename to bypass filtering and execute arbitrary OS commands as the web server user.