XI: Improper Neutralization of Special Elements used in an OS Command
CVE-2025-34286 is a high-severity improper neutralization of special elements used in an OS command vulnerability in XI from Nagios, with a CVSS 3.1 base score of 7.2 out of 10. It can be exploited remotely over the network by an attacker with administrator privileges, without any action from a user. The record lists version 2026R1 as the first without the flaw, so updating XI to that release or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 2.4% chance of exploitation within 30 days, higher than 84% of scored CVEs.
High severity with no evidence of exploitation so far.
What to do
- Update XI to 2026R1 or a later version.
- Update Nagios Xi to 2026 or a later version.
- Read the advisory on nagios.com for workarounds and exact fixed builds.
Affected products and versions
Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.
How the severity score breaks down
- Attack vector
- NetworkCan be exploited remotely over a network, including the internet.
- Attack complexity
- LowNo special conditions are needed; the attack works reliably.
- Privileges required
- HighAdministrator-level access is required first.
- User interaction
- NoneNo action by a victim is required.
- Scope
- UnchangedImpact stays within the vulnerable component.
- Confidentiality
- HighAll data handled by the component can be read.
- Integrity
- HighData or code can be modified at will.
- Availability
- HighThe component can be taken down completely.
Vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H. Scored by NVD.
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 4.0 | 9.4 | Critical | CNA (vulncheck.com) |
| CVSS 3.1 | 7.2 | High | NVD |
Official description
Nagios XI versions prior to 2026R1 contain a remote code execution vulnerability in the Core Config Manager (CCM) Run Check command. Insufficient validation/escaping of parameters used to build backend command lines allows an authenticated administrator to inject shell metacharacters that are executed on the server. Successful exploitation results in arbitrary command execution with the privileges of the Nagios XI web application user and can be leveraged to gain control of the underlying host operating system.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Improper Neutralization of Special Elements used in an OS Command
The product constructs all or part of an OS command using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the intended OS command before it is sent to a downstream component.
How developers prevent this class of flaw
- If at all possible, use library calls rather than external processes to recreate the desired functionality.
- For any data that will be used to generate a command to be executed, keep as much of that data out of external control as possible. For example, in web applications, this may require storing the data locally in the session's state instead of sending it out to the client in a hidden form field.
- For any security checks that are performed on the client side, ensure that these checks are duplicated on the server side, in order to avoid CWE-602. Attackers can bypass the client-side checks by modifying values after the checks have been performed, or by changing the client to remove the client-side checks entirely. Then, these modified values would be submitted to the server.
More Improper Neutralization of Special Elements used in an OS Command vulnerabilities (CWE-78)
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: total).
- Record last changed materially (score, affected products, status or references).
References
Advisories
Patches and release notes
- nagios.com/changelog/nagios-xi/Release Notes
Third-party and government advisories
- vulncheck.com/advisories/nagios-xi-rce-via-run-check-command-in-ccmThird Party Advisory
Other vulnerabilities in XI
- 7.2 High severity
- 7.8 High severity
- 8.8 High severity
- 7.2 High severity
- 7.2 High severity
- 7.2 High severity
Recent Improper Neutralization of Special Elements used in an OS Command vulnerabilities
- 7.2 High severity
- 8.8 High severity
- 9.8 Critical severity
- 7.8 High severity
- 7.8 High severity
- 7.8 High severity
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