Nagios XI versions prior to 2026R1.1 are vulnerable to local privilege escalation due to an unsafe interaction between sudo permissions and application file permissions. A user‑accessible maintenance script may be executed as root via sudo and includes an application file that is writable by a lower‑privileged user. A local attacker with access to the application account can modify this file to introduce malicious code, which is then executed with elevated privileges when the script is run. Successful exploitation results in arbitrary code execution as the root user.
Conclusion & alert: CVE-2025-34288 is rated Moderate Risk (45.8/100): CVSS High severity, with low exploitation likelihood (EPSS 0.13%). Mandatory action: Review affected assets and schedule remediation.
Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.
EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).
| # | Date | Old EPSS score | New EPSS score | Delta (New - Old) |
|---|---|---|---|---|
| 1 | 2026-05-14 | 0.19% | 0.13% | -0.06% |
| 2 | 2026-04-17 | 0.05% | 0.19% | +0.14% |
| 3 | 2025-12-17 | — | 0.05% | — |
Full EPSS history (3 records total)
CVSS metrics for this CVE.
| Base score | Version | Severity | Vector | Exploitability | Impact | Score source |
|---|---|---|---|---|---|---|
| 8.6 | 4.0 | HIGH |
|
— | — | [email protected] |
| 6.7 | 3.1 | MEDIUM |
|
0.8 | 5.9 | [email protected] |
| URL | Tags |
|---|---|
| https://www.nagios.com/changelog/nagios-xi/2026r1-1/ | Release Notes |
| https://www.vulncheck.com/advisories/nagios-xi-privilege-escalation-via-writable-php-include-executed-with-sudo | Third Party Advisory |